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C-R-Newsletter #36    December 31, 2005

Editor's Note: We wrap up CRN's third year, appropriately, with monthly newsletter #36. Here's wishing all our readers a prosperous and joyous 2006!

CRN Goes to Yale
New President at Foresight
CRN Task Force Progress
Bragging About Blogging
A Global Surge Protector?
Inside CRN, Parts 1-5
Milestones & Moving Forward
Feature Essay: Simple Nanofactories vs. Floods of Products


Every month
this newsletter gets you up to date on recent events, but to follow the latest happenings on a daily basis, be sure to check our Responsible Nanotechnology weblog.

=========

CRN Goes to Yale

On Wednesday, December 7, CRN Executive Director Mike Treder gave a talk on "Transforming Society: Ethical Issues in the Nanotech Revolution," at Yale University's Institute for Social and Policy Studies. The presentation was addressed to Yale's Technology and Ethics Working Research Group, an interdisciplinary affiliation of faculty, students, and community members.

A unique feature of this opportunity was its length. The format allows for about 90 minutes of lecture and discussion, followed by a brief break for dinner (delivered to the meeting), and then more informal discussion. With almost three hours to approach a topic, the presenter and group are able to explore it in some depth. Still, at the end several people commented that we had barely scratched the surface of the many serious issues surrounding advanced nanotechnology.


New President at Foresight

The Foresight Nanotech Institute has a new president. On December 9, Scott Mize stepped down after one year in the position, and Marc Lurie was appointed to replace him. Prior to joining Foresight, Lurie founded and as CEO helmed @hand, a software and services company delivering mission-critical mobile solutions to large enterprises.


CRN Task Force Progress

Work is proceeding smoothly for the CRN Global Task Force on Implications and Policy, a diverse group of world-class experts brought together to develop comprehensive recommendations for the safe and responsible use of molecular manufacturing.

Currently, we are completing first drafts on a series of essays that each identifies a specific concern of a task force member about advanced nanotechnology. Almost 20 essays have been written so far. When these are published in anthology form early next year, we will ask for feedback on our ideas, as well as public input on additional concerns.


Bragging About Blogging

Technorati is the equivalent of Google for the blogosphere. Currently tracking 23.4 million sites and 1.8 billion links, Technorati ranks weblogs by what they call 'authority', based on the number of confirmed links from other blog sites.

According to them, CRN's Responsible Nanotechnology blog has more authority than 99.9% of all the others out there. Of course, there are a lot of blogs, and many of them are highly esoteric. But it's nice to know that so many other bloggers have seen the value of referring their readers to our work.


A Global Surge Protector?

Concentration of power is the topic of Mike Treder's most recent Future Brief essay...

Molecular manufacturing represents power: political power, military power, and economic power. When this power becomes available, will a "global surge protector" be needed? If so, how might that be devised and implemented?

Who controls that power and how widely -- how democratically -- it is distributed will make all the difference when nanotechnology is fully developed. Decisions we make before that time will determine whether our world becomes safer or more dangerous; more just or less just; more free or more oppressive.

Chances are you have a surge protector in your home to shield electronic devices from unexpected power surges. Someday soon, we may need protection from unprecedented surges in global political power.

Read the full essay here.


Inside CRN, Parts 1-5

In December, we published a five-part series on our blog that gave a look “inside” CRN. The series of short articles reviewed the process CRN follows in choosing how and what to describe as the likely results of our research into molecular manufacturing.

Commenting on the series, Jamais Cascio of WorldChanging.com said:

CRN looks primarily at the implications of what they term "middle period" nanotech, such as nanofactories -- much more sophisticated than nanomaterials, but not the fantastic nanoassemblers of science fiction. I strongly encourage our readers to check out the recently-concluded "Inside CRN" series at the Center for Responsible Nanotechnology blog. The five posts cover CRN's mission and goals, and explain how their focus differs from other nanotech resources. It's a great introduction to an extremely valuable organization.
 

Milestones & Moving Forward

As we commemorate our 3rd anniversary this month, we are proud of what we've accomplished so far, but mindful that greater challenges await us in 2006. This is important work that few others are doing. To keep moving forward, we will need to grow fast.

A new page on our website lists some of the significant milestones from CRN's first three years. That page also outlines our current priorities—including research, outreach, and development—and suggests several ways in which you can help advance this work.


Feature Essay: Simple Nanofactories vs. Floods of Products
Chris Phoenix, Director of Research, Center for Responsible Nanotechnology

In last month's essay, I explained why even the earliest meter-scale nanofactories will necessarily have a high throughput, manufacturing their own mass in just a few hours. I also explained how a nanofactory can fasten together tiny functional blocks—nanoblocks—to make a meter-scale product. The next question is what range of products an early nanofactory would be able to build.

For several reasons, it is important to know the range and functionality of the products that the nanofactory will produce, and how quickly new products can be developed. Knowing these factors will help to estimate the economic value of the nanofactory, as well as its impacts and implications. The larger the projected value, the more likely it is to be built sooner; the more powerful an early nanofactory is and the faster new products appear, the more disruptive it can be.

Because a large nanofactory can be built only by another nanofactory, even the earliest nanofactories will be able to build other nanofactories. This means that the working parts of the nanofactory will be available as components for other product designs. From this reasoning, we can begin to map the lower bound of nanofactory product capabilities.

This essay is a demonstration of how CRN's thinking and research continue to evolve. In 2003, I published a peer-reviewed paper called "Design of a Primitive Nanofactory" in which I described the simplest nanofactory I could think of. That nanofactory had to do several basic functions, such as transporting components of various sizes, that implied the need for motors and mechanical components also in a variety of sizes, as well as several other functions. However, not long after that paper was published, an even simpler approach was proposed by John Burch and Eric Drexler. Their approach can build large products without ever having to handle large components; small blocks are attached rapidly, directly to the product.

The planar assembly approach to building products is more flexible than the convergent assembly approach, and can use a much more compact nanofactory. Instead of having to transport and join blocks of various sizes within the nanofactory, it only needs to transport tiny blocks from their point of fabrication to the area of the product under construction. (The Burch/Drexler nanofactory does somewhat more than this, but their version could be simplified.) This means that the existence of a nanofactory does not, as I formerly thought, imply the existence of centimeter-scale machinery. A planar nanofactory can probably be scaled to many square centimeters without containing any moving parts larger than a micron.

Large moving parts need to slide and rotate, but small moving parts can be built to flex instead. It is theoretically possible that the simplest nanofactory may not need much in the way of bearings. Large bearings could be simulated by suspending the moving surface with numerous small load-bearing rollers or "walkers" that could provide both low-friction motion and power. This might actually be better than a full-contact surface in some ways; failure of one load-bearing element would not compromise the bearing's operation.

Another important question is what kind of computers the nanofactory will be able to build. Unlike my "primitive nanofactory," a simple planar-assembly nanofactory may not actually need embedded general-purpose computers (CPU's). It might have few enough different components that the instructions for building all the components could be fed in several times over during construction, so that information storage and processing within the nanofactory might be minimal. But even a planar-assembly nanofactory, as currently conceived, would probably have to incorporate large amounts of digital logic (computer-like circuitry) to process the blueprint file and direct the operations of the nanofactory fabricators. This implies that the nanofactory's products could contain large numbers of computers. However, the designs for the computers will not necessarily exist before they are needed for the products.

Any nanofactory will have to perform mechanical motions, and will need a power source for those motions. However, that power source may not be suitable for all products. For example, an early nanofactory might use chemicals for power. It seems more likely to me that it would use electricity, because electric motors are simpler than most chemical processing systems, since chemical systems need to deliver chemicals and remove waste products, while electrical systems only need wires. In that case, products could be electrically powered; it should not be difficult to gang together many nanoscale motors to produce power even for large products.

The ability to fasten nanoscale blocks to selected locations on a growing product implies the ability to build programmable structures at a variety of scales. At the current level of analysis, the existence of a large nanofactory implies the ability to build other large structures. Because the nanofactory would not have to be extremely strong, the products might also not be extremely strong. Further analysis must wait for more information about the design of the nanofactory.

Sensing is an important part of the functionality of many products. An early nanofactory might not need many different kinds of sensing, because its operations would all be planned and commands delivered from outside. One of the benefits of mechanosynthesis of highly cross-linked covalent solids is that any correctly built structure will have a very precise and predictable shape, as well as other properties. Sensing would be needed only for the detection of errors in error-prone operations. It might be as simple as contact switches that cause operations to be retried if something is not in the right place. Other types of sensors might have to be invented for the products they will be used in.

Nanofactories will not need any special appearance, but many products will need to have useful user interfaces or attractive appearances. This would require additional R&D beyond what is necessary for the nanofactory.

The planar assembly approach is a major simplification relative to all previous nanofactory approaches. It may even be possible to build wet-chemistry nanofactory-like systems, as described in my NIAC report that was completed in spring 2005, and bootstrap incrementally from them to high-performance nanofactories. Because of this, it seems less certain that the first large nanofactory will be followed immediately by a flood of products.

A flood of products still could occur if the additional product functionality were pre-designed. Although pre-designed systems will inevitably have bugs that will have to be fixed, rapid prototyping will help to reduce turnaround time for troubleshooting, and using combinations of well-characterized small units should reduce the need for major redesign. For example, given a well-characterized digital logic, it should not be more difficult to build a CPU than to write a software program of equivalent complexity—except that, traditionally, CPU's have required months to build each version of the hardware in the semiconductor fab.

An incremental approach to developing molecular manufacturing might start with a wet-chemical self-assembly system, then perhaps build several versions of mechanosynthetic systems for increasingly higher performance, then start to develop products. Such an incremental approach could require many years before the first general-purpose product design system was available. On the other hand, a targeted development program probably would aim at a dry mechanosynthetic system right from the start, perhaps bypassing some of the wet stages. It would also pre-design product capabilities that were not needed for the basic nanofactory. By planning from the start to take advantage of the capabilities of advanced nanofactories, a targeted approach could develop a general-purpose product design capability relatively early, which then would lead to a potentially disruptive flood of products.


* * * * * * * * * * * * * * * *

FUNDRAISING ALERT!

Recent developments in efforts to roadmap the technical steps toward molecular manufacturing make the work of CRN more important than ever. It is critical that we examine the global implications of this rapidly emerging technology, and begin creating wise and effective solutions. That’s why we have formed the CRN Task Force.

But it won't be easy. We need to grow, and rapidly, to meet the expanding challenge.

Your tax-deductible donation to CRN will help us to achieve that growth. We rely largely on individual donations and small grants for our survival. This is important work and we welcome your participation.

Thank you!

* * * * * * * * * * * * * * * *
 

C-R-Newsletter #35    November 30, 2005

On December 30, 2004, we wrote in our blog: "Things are really starting to heat up around nanotechnology. It looks to us as if 2005 is going to be a huge year for tiny tech."

That prediction was right on the mark. The last 11 months have seen tremendous progress in nanoscience and technology. In this Special Issue of the C-R-Newsletter, we'll highlight a few of the remarkable developments that have made 2005 the Year of Nano.

Two Major MM Papers from Chris Phoenix
CRN Inspires Research on DNA
Nanoscale Engineering at Northwestern
Building Molecular Machines at Rice
Pitt Goes Top-Down & Bottom-Up
Nanotech Roadmap Update
CRN Task Force Progress
Milestones & Moving Forward
Feature Essay: Notes on Nanofactories

Every month this newsletter gets you up to date on recent events, but to follow the latest happenings on a daily basis, be sure to check our Responsible Nanotechnology weblog.

=========

Two Major MM Papers from Chris Phoenix

Earlier this year, CRN's Director of Research Chris Phoenix produced two important papers. "Developing Molecular Manufacturing" was published in March, and then in May, Chris released the findings of a study he performed for NASA's Institute for Advanced Concepts

The first paper proposes that the development of molecular manufacturing can be an incremental process from today's capabilities, and may not be as distant as many believe. Three stages for the development of molecular manufacturing, each with specific milestones, are identified: 1) computer-controlled fabrication of precise molecular structures; 2) exponential growth of the manufacturing base using nanoscale tools to build more tools; 3) integrating nanoscale products into large structures, leading to desktop "nanofactories" that could build advanced products.

The second work, titled "Molecular Manufacturing: What, Why and How," provides a new analysis of existing technological capabilities, including proposed steps from today's nanotech to advanced molecular machine systems. Chris describes two approaches for building the initial basic tools with current technology. Other sections outline incremental improvement from those early tools toward the first integrated nanofactory, and analyze a scalable architecture for a more advanced nanofactory. Product performance and likely applications are discussed, as well as incentives for corporate or government investment in the technology. Finally, considerations and recommendations for a targeted development program are presented.


CRN Inspires Research on DNA

Inspired by one of CRN's Thirty Essential StudiesStudy #10, "What will be required to develop nucleic acid manufacturing and products?" — Frank Boehm wrote "An Investigation of Nucleic Acid/DNA-Based Manufacturing." In this 26-page paper with 242 references, published online in April at the Wise-Nano.org website, Boehm describes many different kinds of tools in the DNA device toolbox, and shows how rapidly development is occurring in this field.


Nanoscale Engineering at Northwestern

One path to molecular manufacturing would use a traditional machining approach to build small systems that can perform increasingly precise operations, similar to what was originally proposed by Richard Feynman. Current university research may be significantly improving the chances of success for this approach.

In September, we reported that researchers at Northwestern had designed a tiny sensitive system for applying and sensing force, welded samples to the device using a new and very powerful nanoscale manufacturing system, then put the device in a tunneling electron microscope (TEM), and watched the tube while they pulled it apart.

Although nothing in this work is atomically precise (with the possible exception of the TEM microscopy), it is getting close. The ability to integrate MEMS, nano-manipulation, FIB, and SEM in a single manufacturing system opens a vast new array of experiments and adds a powerful new part to the nanotech toolbox.


Building Molecular Machines at Rice

Is anyone doing actual lab work on molecular manufacturing?  We're often asked that question, and now we have a positive answer: A research group at Rice University that produced the nanocar. Their reported goal is to "build tiny trucks that could carry atoms and molecules around in miniature factories."

Dr. James Tour, one of the two lead researchers at Rice, says, "The synthesis and testing of nanocars and other molecular machines is providing critical insight in our investigations of bottom-up molecular manufacturing. We'd eventually like to move objects and do work in a controlled fashion on the molecular scale, and these vehicles are great test beds for that. They're helping us learn the ground rules."


Pitt Goes Top-Down & Bottom-Up

In a span of two weeks in late October, we read a remarkable pair of reports about important nanotechnology work taking place at the University of Pittsburgh's Institute of NanoScience and Engineering.

The first account told of Pitt scientists using an advanced nanofabrication system to create the world's smallest chess pieces, approximately 400 nanometers wide. Although this new top-down technology is not quite atomically precise, it does use an electron beam focused to less than two nanometers, allowing researchers to create nanometer-scale structures.

In the second instance, we learned more about the impressive progress being made by Christian Schafmeister, assistant professor of chemistry at the University of Pittsburgh. His experimental work—designing modular molecules that link together in predictable ways with pairs of stiff bonds—will enable, for the first time, the quick manufacture of sturdy, predictable nanostructures. Because the molecules are large enough to have interesting functions and rigid, designed shapes, they hold great promise as nanoscale parts for future atomically precise nanoscale machines.


Nanotech Roadmap Update

Last summer, the Foresight Nanotech Institute and the Battelle research organization announced that they would work together to produce a Technology Roadmap for Productive Nanosystems. This effort is being funded in part by the Waitt Family Foundation, as well as by corporate supporters including Sun Microsystems. The published Roadmap Background states a clear intention to close the "implementation gap" separating today's nanostructures from the "complex productive nanosystems of the future."

They say that biopolymers (DNA, protein) can provide a basis for the design and fabrication of atomically precise, self-assembling composite structures—forming molecular components that bind and organize diverse nanostructures (nanotubes, macromolecules) to form molecular machine systems. Further steps are expected to show the way from the production of 1-dimensional polymers to 2- and 3-dimensional covalent structures, from self-assembly to simpler, mechanical construction methods, and from microscopic systems to desktop-scale factories.

Ultimately, these advanced productive nanosystems (molecular manufacturing systems) should enable the fabrication of large, complex products cleanly, efficiently, and at low cost. According to Eric Drexler, one of the lead researchers on the Roadmap project, nanofactory products could include:

bulletDesktop computers with a billion processors
bulletInexpensive, efficient solar energy systems
bulletMedical devices able to destroy pathogens and repair tissues
bulletMaterials 100 times stronger than steel
bulletSuperior military systems
bulletAdditional molecular manufacturing systems


CRN Task Force Progress

The July announcement of an initiative to create a Technology Roadmap for Productive Nanosystems (see above) motivated CRN to organize a parallel process of study and action: the CRN Global Task Force on Implications and Policy. Bringing together a diverse group of world-class experts from multiple disciplines, CRN is leading an historic, collaborative effort to develop comprehensive recommendations for the safe and responsible use of molecular manufacturing.

We now have more than 50 participants from six different countries on the CRN Task Force. Currently, the group is working on a series of short essays to identify specific concerns that must be addressed. When these are published in anthology form early next year, we will ask for feedback on our ideas, as well as public input on additional concerns.


Milestones & Moving Forward

As CRN approaches our 3rd anniversary, we are proud of what we've accomplished so far, but mindful that greater challenges await us in 2006. This is important work that few others are doing. To keep moving forward, we will need to grow fast.

A new page on our website lists some of the significant milestones from CRN's first three years. That page also outlines our current priorities—including research, outreach, and development—and suggests several ways in which you can help advance this work.


Feature Essay: Notes on Nanofactories
Chris Phoenix, Director of Research, Center for Responsible Nanotechnology

This month's science essay is prompted by several questions about nanofactories that I've received over the past few months. I'll discuss the way in which nanofactories combine nanoscale components into large integrated products; the reason why a nanofactory will probably take about an hour to make its weight in product; and how to cool a nanofactory effectively at such high production rates.

In current nanofactory designs, sub-micron components are made at individual workstations and then combined into a product. This requires some engineering above and beyond what would be needed to build a single workstation. Tom Craver, on our blog, suggested that there might be a transitional step, in which workstations are arranged in a two-dimensional sheet and make a thin sheet of product. The sheet of manufacturing systems would not have to be flat; it could be V-folded, and perhaps a solid product could be pushed out of a V-folded arrangement of sheets. With a narrow folding angle, the product might be extruded at several times the mechanosynthetic deposition rate.

Although the V-fold idea is clever, I think it's not necessary. Once you can build mechanosynthetic systems that can build sheets of product, you're most of the way to a 3D nanofactory. For a simple design, each workstation produces a sub-micron "nanoblock" of product (each dimension being the thickness of the product sheet) rather than a connected sheet of product. Then you have the workstations pass the blocks "hand over hand" to the edge of the workstation sheet. In a primitive nanofactory design, much of the operational complexity would be included in the incoming control information rather than the nanofactory's hardware. This implies that each workstation would have a general-purpose robot arm or other manipulator capable of passing blocks to the next workstation.

After the blocks get to the edge of the sheet, they are added to the product. Instead of the product being built incrementally at the surface of V-folded sheets, the sheets are stacked fully parallel, just like a ream of paper, and the product is built at the edge of the ream.

Three things will limit the product ‘extrusion’ speed:

  1. The block delivery speed. This would be about 1 meter per second, a typical speed for mechanisms at all scales. This is not a significant limitation.
  2. The speed of fastening a block in place. Even a 100-nanometer block has plenty of room for nanoscale mechanical fasteners that can basically just snap together as fast as the blocks can be placed. Fasteners that work by molecular reactions could also be fast.
  3. The width (or depth, depending on your point of view) of the sheet: how many workstations are supplying blocks to each workstation-width edge-of-sheet. The width of the sheet stack is limited by the ability to circulate cooling fluid, but it turns out that even micron-wide channels can circulate fluid for several centimeters at moderate pressure. So you can stack the sheets quite close together, making a centimeter-thick slab. With 100-nanometer workstations, that will have several thousand workstations supplying each 100-nanometer-square edge-of-stack area. If a workstation takes an hour to make a 100-nanometer block, then you're depositing several millimeters per hour. That's if you build the product solid; if you provide a way to shuffle blocks around at the product-deposition face, you can include voids in the product, and 'extrude' much faster; perhaps a mm per second.

Tom pointed out that a nanofactory that built products by block deposition would require extra engineering in several areas, such as block handling mechanisms, block fasteners, and software to control it all. All this is true, but it is the type of problem we have already learned to solve. In some ways, working with nanoblocks will be easier than working with today's industrial robots; surface forces will be very convenient, and gravity will be too weak to cause problems.

On the same blog post, Jamais Cascio asked why I keep saying that a nanofactory will take about an hour to make its weight of product. The answer is simple: If the underlying technology is much slower than that, it won't be able to build a kilogram-scale nanofactory in any reasonable time. And although advanced nanofactories might be somewhat faster, a one-hour nanofactory would be revolutionary enough.

A one-kilogram one-hour nanofactory could, if supplied with enough feedstock and energy, make thousands of tons of nanofactories or products in a single day. It doesn't much matter if nanofactories are faster than one hour (3600 seconds). Numbers a lot faster than that start to sound implausible. Some bacteria can reproduce in 15 minutes (900 seconds). Scaling laws suggest that a 100-nm scanning probe microscope can build its mass in 100 seconds. (The non-manufacturing overhead of a nanofactory—walls, computers, and so on—would probably weigh less than the manufacturing systems, imposing a significant but not extreme delay on duplicating the whole factory.) More advanced molecule-processing systems could, in theory, process their mass even more quickly, but with reduced flexibility.

On the slower side, the first nanofactory can't very well take much longer than an hour to make its mass, because if it did, it would be obsoleted before it could be built. It goes like this: A nanofactory can only be built by a smaller nanofactory. The smallest nanofactory will have to be built by very difficult lab work. So you'll be starting from maybe a 100-nm manufacturing system (10-15 grams) and doubling sixty times to build a 103 gram nanofactory. Each doubling takes twice the make-your-own-mass time. So a one-hour nanofactory would take 120 hours, or five days. A one-day nanofactory would take 120 days, or four months. If you could double the speed of your 24-hour process in two months (which gives you sixty day-long "compile times" to build increasingly better hardware using the hardware you have), then the half-day nanofactory would be ready before the one-day nanofactory would.

Tom Craver pointed out that if the smaller nanofactory can be incorporated into the larger nanofactory that it's building, then doubling the nanofactory mass would take only half as long. So, a one-day nanofactory might take only two months, and a one-hour nanofactory less than three days. Tom also pointed out that if a one-day tiny-nanofactory is developed at some point, and its size is slowly increased, then when the technology for a one-hour nanofactory is developed, a medium-sized one-hour nanofactory could be built directly by the largest existing one-day nanofactory, saving part of the growing time.

In my "primitive nanofactory" paper, which used a somewhat inefficient physical architecture in which the fabricators were a fraction of the total mass, I computed that a nanofactory on that plan could build its own mass in a few hours. This was using the Merkle pressure-controlled fabricator, (see "Casing an Assembler"), with a single order of magnitude speedup to go from pressure to direct drive.

In summary, the one-hour estimate for nanofactory productivity is probably within an order of magnitude of being right.

The question about cooling a nanofactory was asked at a talk I gave a few weeks ago, and I don't remember who asked it. To build a kilogram per hour of diamond requires rearranging on the order of 1026 covalent bonds in an hour. The bond energy of carbon is approximately 350 kJ/mol, or 60 MJ/kg. Spread over an hour, that much energy would release 16 kilowatts, about as much as a plug-in electric heater.

Of course, you don't want a nanofactory to glow red-hot. And the built-in computers that control the nanofactory will also generate quite a bit of heat--perhaps even more than the covalent reactions themselves. So, fluid cooling looks like a good idea. It turns out that, although the inner features of a nanofactory will be very small—on the order of one micron—cooling fluid can be sent for several centimeters down a one-micron channel with only a modest pressure drop. This means that the physical architecture of the nanofactory will not need to be adjusted to accommodate variable-sized tree-structured cooling pipes.

In the years I have spent thinking about nanofactory design, I have not encountered any problem that could not be addressed with standard engineering. Of course, engineering in a new domain will present substantial challenges and require a lot of work. However, it is not safe to assume that some unexpected problem will arise to delay nanofactory design and development. As work on enabling technologies progresses, it is becoming increasingly apparent that nanofactories can be addressed as an integration problem rather than a fundamental research problem. Although their capabilities seem futuristic, their technology may be available before most people expect it.
 

C-R-Newsletter #34    October 16, 2005

Major Advances in Nanoscale Engineering
New Technical Information Freely Available
CRN Task Force Progress Report
Dark Visions of a Fantastic Future
CRN Interviewed re Military Nanotechnology
CRN Gets Podcasted
We're on CNET’s Blog 100 List
CRN Goes to Chicago, Again
CRN Goes to San Francisco
CRN Goes to Michigan
CRN Goes to Seattle
Feature Essay: Early Applications of Molecular Manufacturing

=========

What a whirlwind! We'll fill you in on recent events here, but to keep up with the latest happenings on a daily basis, be sure to check our Responsible Nanotechnology weblog.

Also, please notice the FUNDRAISING ALERT at the end of this newsletter.


Major Advances in Nanoscale Engineering

There are several possible paths to molecular manufacturing. Eric Drexler favors starting with biopolymer-based systems and improving them incrementally. Robert Freitas and Ralph Merkle propose using scanning probe microscopes to do direct mechanosynthesis of diamondoid systems. Another researcher, Josh Hall, favors a third path: using a more traditional machining approach to build small systems that can perform increasingly precise operations, similar to what was originally proposed by Richard Feynman.

Exciting work at Northwestern University could significantly improve the chances of the third approach succeeding. Researchers there recently designed a tiny sensitive system for applying and sensing force, had samples welded to the device using a new and very powerful nanoscale manufacturing system, then put the device in a tunneling electron microscope (TEM) and watched the tube while they pulled it apart.

Although nothing in this work is atomically precise (with the possible exception of the TEM microscopy), it's getting close. The ability to integrate MEMS, nano-manipulation, FIB, and SEM in a single manufacturing system opens a vast new array of experiments and adds a powerful new part to the nanotech toolbox.


New Technical Information Freely Available

Now posted online is "Design and Analysis of a Molecular Tool for Carbon Transfer in Mechanosynthesis" [PDF] by Damian G. Allis and K. Eric Drexler. This important new paper introduces a novel carbon-transfer tool design (named "DC10c"), the first predicted to exhibit several significant properties in combination.

Also available online is Kinematic Self-Replicating Machines by Robert A. Freitas Jr. and Ralph C. Merkle. This is the most comprehensive review ever published about self-replicating machine systems, specifically kinematic self-replicating machines: systems in which actual physical objects, not mere patterns of information, undertake their own replication. The book presents for the first time a detailed 137-dimensional map of the entire kinematic replicator design space to assist future engineering efforts. It has been cited in two articles appearing in the journal Nature this year and appears well on its way to becoming the classic reference in the field.

It's important to note that most of the systems described in KSRM are only self-replicating in the sense that a set of blacksmith's tools is self-replicating. The machinery can be used to make a physical copy, but only under external control, and/or with artificially processed feedstock. Although runaway independent self-replication has often been cited as a theoretical danger, it is not a risk of currently planned molecular manufacturing development.


CRN Task Force Progress Report

Recently CRN announced the formation of a new Global Task Force to study the societal implications of advanced nanotechnology. Bringing together a diverse group of world-class experts from multiple disciplines, CRN is leading an historic, collaborative effort to develop comprehensive recommendations for the safe and responsible use of molecular manufacturing.

We're now up to 45 participants from six different countries on the CRN Task Force. In addition, four organizations are publicly supporting this effort: the Society of Manufacturing Engineers, the Society of Police Futurists International, the Nanoethics Group, and the Nanotechnology Now web portal.

Currently underway is a major effort to identify and classify the most important questions to be asked and answered in order to propose workable solutions to the challenges posed by this powerful new technology. We expect to publish our initial findings around the end of this year.


Dark Visions of a Fantastic Future

Flying cars are everywhere… large regions of the earth are under transparent domes with controlled weather… elsewhere, single buildings rise miles into the sky… huge areas of the ocean are covered with solar cells… tiny cameras watch everyone everywhere all the time, making sure crime does not pay…

In the near future, each of these visions will become possible. They could become reality. But will they? And should they?

That's from "Dark Visions of a Fantastic Future," a new essay written by CRN Executive Director Mike Treder for Future Brief. Here is the final paragraph:

Visions of a fantastic future could come true in our lifetimes. As we dream of the wonderful possibilities, we should take care also to envision darker scenarios. Because unless we can prevent the worst of the dangers—and there are many—we will deny ourselves any hope of realizing the benefits.


CRN Interviewed re Military Nanotechnology

For their most recent monthly report, a special issue on "Nanotechnology and the Military," Nanotech-Now.com interviewed CRN's Chris Phoenix and Mike Treder. Under the heading of "Considering Military and Homeland Security Applications of Advanced Nanotechnology," they published our thoughts about automated weapons, arms races, surveillance and privacy, economic disruption, and more.


CRN Gets Podcasted

A podcast program called Small World conducted an interview this month with CRN Executive Director Mike Treder. Topics covered were the various definitions of nanotechnology; practical applications of nanotechnology today and in the near future; nanofactories; the impact of nanotechnology on the economy; military and terrorist use of nanotechnology; the National Nanotechnology Initiative; and much more. The completed feature is about 20 minutes long and can be downloaded online.


We're on CNET's Blog 100 List

With more than 14 million blogs in existence and another 80,000 being created each day, how is a person supposed to find the ones worth reading? That's the question asked by CNET News.com, and they answer it with their Blog 100 list.

We are very proud that our Responsible Nanotechnology blog was chosen by CNET News. It's quite an honor to be ranked in the top 100 technology-oriented blogs among such stiff competition. We will strive to remain worthy of this recognition.


CRN Goes to Chicago, Again

CRN's Chris Phoenix gave a talk called "What is nanotechnology? And what does it have to do with assembly technology?" at the Assembly Technology Expo in Chicago last month (Mike Treder was in Chicago two months ago for the World Future Society's annual meeting). Chris explained how and why molecular manufacturing goes far beyond molecular "self-assembly" techniques.


CRN Goes to San Francisco

CRN is proud to be a media sponsor for the 13th Foresight Conference on Advanced Nanotechnology. The title of the conference this year is "Advancing Beneficial Nanotechnology: Focusing on the Cutting Edge," and it will be divided into three stand-alone, complementary sessions — Vision, Applications & Policy, and Research — spread over six days.

During the "Vision" session on Sunday, Chris Phoenix will deliver a talk titled "Designing a Revolution." The conference is October 22-27, 2005, in San Francisco, California. They've got a great lineup of speakers, so we hope to see you there.


CRN Goes to Michigan

From San Francisco, Chris Phoenix will fly to Michigan where he will address the 1st International IFAS Conference on Nanotechnology, sponsored by Michigan State University's Agrifood Nanotechnology Project. The conference will focus on what nanotech and nanofood can learn from biotech and GMOs. Chris will be part of a concluding panel discussion.


CRN Goes to Seattle

From Michigan, Chris Phoenix will fly to Seattle where he will address the SAMPE (Society for the Advancement of Material and Process Engineering) Fall Technical Conference. Chris will participate in a panel discussion on occupational safety issues related to nanotechnology.


Feature Essay: Early Applications of Molecular Manufacturing
Chris Phoenix, Director of Research, Center for Responsible Nanotechnology

Molecular manufacturing (MM) will be able to build a wide variety of products -- but only if their designs can be specified. Recent science essays have explained some reasons why nanofactory products may be relatively easy to design in cases where we know what we want, and only need to enter the design into a CAD program. Extremely dense functionality, strong materials, integrated computers and sensors, and inexpensive full-product rapid prototyping will combine to make product design easier.

However, there are several reasons why the design of certain products may be quite difficult. Requirements for backward compatibility, advanced requirements, complex or poorly understood environments, regulations, and lack of imagination are only a few of the reasons why a broad range of nanofactory products will be difficult to get right. Some applications will be a lot easier than others.

Products are manufactured for many purposes, including transportation, recreation, communication, medical care, basic needs, military support, and environmental monitoring, among others. This essay will consider a few products in each of these categories, in order to convey a sense of the extent to which the initial MM revolution, though still profound, may be limited by practical design problems.

Transportation is simple in concept: merely move objects or people from one place to another place. Efficient and effective transportation is quite a bit more difficult. Any new transportation system needs to be safe, efficient, rapid, and compatible with a wide range of existing systems. If it travels on roads, it will need to comply with a massive pile of regulations. If it uses installed pathways (future versions of train tracks), space will have to be set aside for right-of-ways. If it flies, it will have to be extremely safe to reassure those using it and avoid protest from those underneath.

Despite these problems, MM could produce fairly rapid improvements in transportation. There would be nothing necessarily difficult about designing a nanofactory-built automobile that exceeded all existing standards. It would be very cheap to build, and fairly efficient to operate -- although air resistance would still require a lot of fuel. Existing airplanes also could be replaced by nanofactory-built versions, once they were demonstrated to be safe. In both cases, a great deal of weight could be saved, because the motors would be many orders of magnitude smaller and lighter, and the materials would be perhaps 100 times as strong. Low-friction skins and other advances would follow shortly.

Molecular manufacturing could revolutionize access to space. Today's rockets can barely get there; they spend a lot of energy just getting through the atmosphere, and are not as efficient as they could be. The most efficient rocket nozzle varies as atmospheric pressure decreases, but no one has built a variable-nozzle rocket. Far more efficient, of course, would be to use an airplane to climb above most of the atmosphere, as Burt Rutan did to win the X Prize. But this has never been an option for large rockets. Another problem is that the cost of building rockets is astronomical: they are basically hand-built, and they must use advanced technology to minimize weight. This has caused rocketry to advance very slowly. A single test of a new propulsion concept may cost hundreds of millions of dollars.

When it becomes possible to build rockets with automated factories and materials ten times as strong and light as today's, rockets will become cheap enough to test by the dozen. Early advances could include disposable airplane components to reduce fuel requirements; far less weight required to keep a human alive in space; and far better instrumentation on test flights -- instrumentation built into the material itself -- making it easier and faster to determine the cause of failures. It seems likely that the cost of owning and operating a small orbital rocket might be no more than the cost of owning a light airplane today. Getting into space easily, cheaply, and efficiently will allow rapid development of new technologies like high-powered ion drives and solar sails. However, all this will rely on fairly advanced engineering -- not only for the advanced propulsion concepts, but also simply for the ability to move through the atmosphere quickly without burning up.

Recreation is typically an early beneficiary of inventiveness and new technology. Because many sports involve humans interacting directly with simple objects, advances in materials can lead to rapid improvements in products. Some of the earliest products of nanoscale technologies (non-MM nanotechnology) include tennis rackets and golf balls, and such things will quickly be replaced by nano-built versions. But there are other forms of recreation as well. Video games and television absorb a huge percentage of people's time. Better output devices and faster computers will quickly make it possible to provide users with a near-reality level of artificial visual and auditory stimulus. However, even this relatively simple application may be slowed by the need for interoperability: high-definition television has suffered substantial delays for this reason.

A third category of recreation is neurotechnology, usually in the form of drugs such as alcohol and cocaine. The ability to build devices smaller than cells implies the possibility of more direct forms of neurotechnology. However, safe and legal uses of this are likely to be quite slow to develop. Even illegal uses may be slowed by a lack of imagination and understanding of the brain and the mind. A more mundane problem is that early MM may be able to fabricate only a very limited set of molecules, which likely will not include neurotransmitters.

Medical care will be a key beneficiary of molecular manufacturing. Although the human body and brain are awesomely complex, MM will lead to rapid improvement in the treatment of many diseases, and before long will be able to treat almost every disease, including most or all causes of aging. The first aspect of medicine to benefit may be minimally invasive tests. These would carry little risk, especially if key results were verified by existing tests until the new technology were proved. Even with a conservative approach, inexpensive continuous screening for a thousand different biochemicals could give doctors early indications of disease. (Although early MM may not be able to build a wide range of chemicals, it will be able to build detectors for many of them.) Such monitoring also could reduce the consequences of diseases inadvertently caused by medical treatment by catching the problem earlier.

With full-spectrum continuous monitoring of the body's state of health, doctors would be able to be simultaneously more aggressive and safer in applying treatments. Individual, even experimental approaches could be applied to diseases. Being able to trace the chemical workings of a disease would also help in developing more efficient treatments for it. Of course, surgical tools could become far more delicate and precise; for example, a scalpel could be designed to monitor the type and state of tissue it was cutting through. Today, in advanced arthroscopic surgery, simple surgical tools are inserted through holes the size of a finger; a nano-built surgical robot with far more functionality could be built into a device the width of an acupuncture needle.

In the United States today, medical care is highly regulated, and useful treatments are often delayed by many years. Once the technology becomes available to perform continuous monitoring and safe experimental treatments, either this regulatory system will change, or the U.S. will fall hopelessly behind other countries. Medical technologies that will be hugely popular with individuals but may be opposed by some policy makers, including anti-aging, pro-pleasure, and reproductive technologies, will probably be developed and commercialized elsewhere.

Basic needs, in the sense of food, water, clothing, shelter, and so on, will be easy to provide with even minimal effort. All of these necessities, except food, can be supplied with simple equipment and structures that require little innovation to develop. Although directly manufacturing food will not be so simple, it will be easy to design and create greenhouses, tanks, and machinery for growing food with high efficiency and relatively little labor. The main limitation here is that without cleverness applied to background information, system development will be delayed by having to wait for many growing cycles. For this reason, systems that incubate separated cells (whether plant, animal, or algae) may be developed more quickly than systems that grow whole plants.

The environment already is being impacted as a byproduct of human activities, but molecular manufacturing will provide opportunities to affect it deliberately in positive ways. As with medicine, improving the environment will have to be done with careful respect for the complexity of its systems. However, also as with medicine, increased ability to monitor large areas or volumes of the environment in detail will allow the effects of interventions to be known far more quickly and reliably. This alone will help to reduce accidental damage. Existing damage that requires urgent remediation will in many cases be able to be corrected with far fewer side effects.

Perhaps the main benefit of molecular manufacturing for environmental cleanup is the sheer scale of manufacturing that will be possible when the supply of nanofactories is effectively unlimited. To deal with invasive species, for example, it may be sufficient to design a robot that physically collects and/or destroys the organisms. Once designed and tested, as many copies as required could be built, then deployed across the entire invaded range, allowed to work in parallel for a few days or weeks, and then collected. Such systems could be sized to their task, and contain monitoring apparatus to minimize unplanned impacts. Because robots would be lighter than humans and have better sensors, they could be designed to do significantly less damage and require far fewer resources than direct human intervention. However, robotic navigation software is not yet fully developed, and it will not be trivial even with million-times better computers. Furthermore, the mobility and power supply of small robots will be limited. Cleanup of chemical contamination in soil or groundwater also may be less amenable to this approach without significant disruption.

Advanced military technology may have an immense impact on our future. It seems clear that even a modest effort at developing nano-built weapon systems will create systems that will be able to totally overwhelm today's systems and soldiers. Even something as simple as multi-scale semi-automated aircraft could be utterly lethal to exposed soldiers and devastating to most equipment. With the ability to build as many weapons as desired, and with motors, sensors, and materials that far outclass biological equivalents, there would be no need to put soldiers on the battlefield at all. Any military operation that required humans to accompany its machines would quickly be overcome. Conventional aircraft could also be out-flown and destroyed with ease. In addition to offensive weapons, sensing and communications networks with millions if not billions of distributed components could be built and deployed. Software design for such things would be far from trivial, however.

It is less clear that a modest military development effort would be able to create an effective defense against today's high-tech attack systems. Nuclear explosives would have to be stopped before the explosion, and intercepting or destroying missiles in flight is not easy even with large quantities of excellent equipment. Hypersonic aircraft and battle lasers are only now being developed, and may be difficult to counter or to develop independently without expert physics knowledge and experience. However, even a near parity of technology level would give the side with molecular manufacturing a decisive edge in a non-nuclear exchange, because they could quickly build so many more weapons.

It is also uncertain what would happen in an arms race between opponents that both possessed molecular manufacturing. Weapons would be developed very rapidly up to a certain point. Beyond that, new classes of weapons would have to be invented. It is not yet known whether offensive weapons will in general be able to penetrate shields, especially if the weapons of both sides are unfamiliar to their opponents. If shields win, then development of defensive technologies may proceed rapidly until all sides feel secure. If offense wins, then a balance of terror may result. However, because sufficient information may allow any particular weapon system to be shielded against, there may be an incentive to continually develop new weapons.

This essay has focused on the earliest applications of molecular manufacturing. Later developments will benefit from previous experience, as well as from new software tools such as genetic algorithms and partially automated design. But even a cursory review of the things we can plan for today and the problems that will be most limiting early in the technology's history shows that molecular manufacturing will rapidly revolutionize many important areas of human endeavor.


* * * * * * * * * * * * * * * *

FUNDRAISING ALERT!

Recent developments in efforts to roadmap the technological steps towards molecular manufacturing make the work of CRN even more important. It is critical that we examine the global implications of this rapidly emerging technology, and begin designing wise and effective policy. That's why we have formed the CRN Task Force.

But it won't be easy. We need to grow, and rapidly, to meet the expanding challenge.

Your donation to CRN will help us to achieve that growth. We rely largely on individual donations and small grants for our survival.

To make a contribution on-line, click here. This is important work and we welcome your participation.


Thank you!

* * * * * * * * * * * * * * * *
 

C-R-Newsletter #33    August 31, 2005

CRN Forms Policy Task Force
Eric Drexler Joins Nanorex
Connecticut Schools Go Nano
NASA Website Covers CRN Work
CRN Goes to Vermont
CRN Goes to Chicago
CRN Goes to Bootcamp
Dimensions of Development
13th Foresight Conference
Feature Essay: Molecular Manufacturing Design Software

=========

We're a little late getting the C-R-Newsletter out this month, but as you can see, we've been extremely busy. To keep up with the latest happenings on a daily basis, be sure to check our Responsible Nanotechnology weblog.
 

CRN Forms Policy Task Force

The big news this month is that CRN announced the formation of a new Global Task Force to study the societal implications of advanced nanotechnology. Bringing together a diverse group of world-class experts from multiple disciplines, CRN will lead an historic, collaborative effort to develop comprehensive policy recommendations for the safe and responsible use of molecular manufacturing. 

Just two weeks after the initial announcement, which mentioned four "charter members" of the CRN Task Force, we're up to 39 participants from six different countries. In addition, three organizations are publicly supporting this effort: the Society of Manufacturing Engineers, the Society of Police Futurists International, and the Nanotechnology Now web portal.

Several online planning sessions have been held, and the CRN Task Force is now beginning its initial task: to itemize the necessary information that must be available in order to design wise and effective policy.

 

Eric Drexler Joins Nanorex

Nanorex, a molecular engineering software company based in Michigan, has named Dr. K. Eric Drexler as the company's Chief Technical Advisor. The company said that Drexler will play a leading role in shaping Nanorex's product strategy and advancing the company’s academic outreach programs.

Often described as the 'father of nanotechnology', Eric Drexler is on the Board of Advisors for CRN. His groundbreaking theoretical research has been the basis for three books, including Nanosystems: Molecular Machinery, Manufacturing, and Computation, and numerous journal articles. Last year, he collaborated with Chris Phoenix, CRN's Director of Research, on "Safe Exponential Manufacturing", published in the Institute of Physics journal Nanotechnology.

In 1986, Drexler founded the Foresight Nanotech Institute, a non-profit think tank and public interest organization focused on nanotechnology. He was awarded a PhD from MIT in Molecular Nanotechnology (the first degree of its kind). Drexler is expected to be deeply involved in the project to develop a Technology Roadmap for Productive Nanosystems, recently announced by Foresight and the Battelle research organization.


Connecticut Schools Go Nano

Connecticut Governor M. Jodi Rell has enacted a new law requiring the Commissioner of Higher Education in her state to review the inclusion of nanotechnology, molecular manufacturing and advanced and developing technologies at institutions of higher education.

CRN is pleased to note that this measure specifically designates molecular manufacturing as something that should be studied for inclusion in the curriculum at institutions of higher education. We encourage other states -- and indeed, other countries -- to follow Connecticut's lead.

 

 

NASA Website Covers CRN Work

The NASA Institute for Advanced Concepts (NIAC), an independent, NASA-funded organization located in Atlanta, Georgia, was created to promote forward-looking research on radical space technologies that will take 10 to 40 years to come to fruition. Last year, NIAC awarded a grant to Chris Phoenix, CRN's Director of Research, to conduct a feasibility study of nanoscale manufacturing.

On NASA's website, an article titled "The Next Giant Leap" highlights the work NIAC is funding in nanotechnology research, and includes a description of the 112-page report Chris presented to them. We congratulate Chris on this much-deserved recognition. 


CRN Goes to Vermont

 

In late July, CRN principals Mike Treder and Chris Phoenix were invited to participate in a special workshop on 'geoethical nanotechnology', held at a beautiful mountain retreat in Vermont. Our gracious host was Martine Rothblatt, CEO of United Therapeutics Corporation, and founder of the Terasem Movement Foundation.

 

Among those making presentations were Ray Kurzweil, CEO of Kurzweil Technologies; Professor Frank Tipler of Tulane University; Douglas Mulhall, author of Our Molecular Future; and Dr. Barry Blumberg, a Nobel Prize-winner in medicine and Founding Director of the NASA Astrobiology Institute. CRN's PowerPoint presentation for the event is available online here.

 

Geoethical nanotechnology is defined as: the development and implementation under a global regulatory framework of machines capable of assembling molecules into a wide variety of objects, in a broad range of sizes, and in potentially vast quantities.

 


CRN Goes to Chicago

 

Also in July, CRN Executive Director Mike Treder gave talks at two events in Chicago. First, at a special nanotech symposium [PDF], Mike delivered a presentation called "The Flat Horizon Problem: Nanotechnology on an Upward Slope" [PPT].

 

Then, during the annual conference of the World Future Society, Mike made a speech titled, "Do Sweat the Small Stuff: Why Everyone Should Care About Nanotechnology" [PPT]. The conference, WorldFuture 2005: Foresight, Innovation, and Strategy, was managed excellently and enjoyed huge attendance.

 


CRN Goes to Bootcamp

 

In mid-July, CRN Research Director Chris Phoenix spent four days in Washington DC at a Nano Training Bootcamp sponsored by the ASME. He called it "quite a brain-stretcher." Topics included quantum mechanics, optics, thermoelectrics, nanolithography, and much more. Chris provided us with extensive blog reports during the event, so you can read about all the tech-talk from Day One, Day Two, Day Three, and Day Four.

 

 

Dimensions of Development

 

Many factors will determine how soon and how safely molecular manufacturing is integrated into society, including where, how openly, and how rapidly it is developed. Because nanotech manufacturing could be so disruptive and destabilizing, it is essential that we learn as much as possible about those factors and others. The more we know, the better we may be able to guide and manage this revolutionary transformation.

 

Mike Treder's latest essay for Future Brief describes six different dimensions — Number, Style, Venue, Approach, Program, and Pace — along which molecular manufacturing may be developed. Making effective policy for the safe and responsible use of advanced nanotechnology will require a deep and comprehensive understanding of all six dimensions. To be effective, a coordinated and integrated strategy of multiple complimentary policies must be designed and implemented. (Note: At the time the essay was published, the CRN Global Task Force on Implications and Policy had not yet been announced.)

 

 

13th Foresight Conference

CRN is proud to be a media sponsor for the 13th Foresight Conference on Advanced Nanotechnology. The title of the conference this year is "Advancing Beneficial Nanotechnology: Focusing on the Cutting Edge," and it will be divided into three stand-alone, complementary sessions — Vision, Applications & Policy, and Research — spread over six days.

The conference is October 22-27, 2005, in San Francisco, California. They've got a great lineup of speakers, so we hope to see you there.
 

Feature Essay: Molecular Manufacturing Design Software
Chris Phoenix, Director of Research, CRN

Nanofactories, controlled by computerized blueprints, will be able to build a vast range of high performance products. However, efficient product design will require advanced software.

Different kinds of products will require different approaches to design. Some, such as high-performance supercomputers and advanced medical devices, will be packed with functionality and will require large amounts of research and invention. For these products, the hardest part of design will be knowing what you want to build in the first place. The ability to build test hardware rapidly and inexpensively will make it easier to do the necessary research, but that is not the focus of this essay.

There are many products that we easily could imagine and that a nanofactory easily could build if told exactly how. But as any computer programmer knows, it's not easy to tell a computer what you want it to do — it's more or less like trying to direct a blind person to cook a meal in an unfamiliar kitchen. One mistake, and the food is spilled or the stove catches fire.

Computer users have an easier time of it. To continue the analogy, if the blind person had become familiar with the kitchen, instructions could be given on the level of "Get the onions from the left-hand vegetable drawer" rather than "Move your hand two inches to your right... a bit more... pull the handle... bend down and reach forward... farther... open the drawer... feel the round things?" It is the job of the programmer to write the low-level instructions that create appliances from obstacles.

Another advantage of modern computers, from the user's point of view, is their input devices. Instead of typing a number, a user can simply move a mouse, and a relatively simple routine can translate its motion into the desired number, and the number into the desired operation such as moving a pointer or a scroll bar.

Suppose I wanted to design a motorcycle. Today, I would have to do engineering to determine stresses and strains, and design a structure to support them. The engineering would have to take into account the materials and fasteners, which in turn would have to be designed for inexpensive assembly. But these choices would limit the material properties, perhaps requiring several iterations of design. And that's just for the frame.

Next, I would have to choose components for a suspension system, configure an engine, add an electrical system and a braking system, and mount a fuel tank. Then, I would have to design each element of the user interface, from the seat to the handgrips to the lights behind the dials on the instrument panel. Each thing the user would see or touch would have to be made attractive, and simultaneously specified in a way that could be molded or shaped. And each component would have to stay out of the way of the others: the engine would have to fit inside the frame, the fuel tank might have to be molded to avoid the cylinder heads or the battery, and the brake lines would have to be routed from the handlebars and along the frame, adding expense to the manufacturing process and complexity to the design process.

As I described in last month's essay, most nanofactory-built human-scale products will be mostly empty space due to the awesomely high performance of both active and passive components. It will not be necessary to worry much about keeping components out of each other's way, because the components will be so small that they can be put almost anywhere. This means that, for example, the frame can be designed without worrying where the motor will be, because the motor will be a few microns of nanoscale motors lining the axles. Rather than routing large hydraulic brake lines, it will be possible to run highly redundant microscopic signal lines controlling the calipers — or more likely, the regenerative braking functionality built into the motors.

It will not be necessary to worry about design for manufacturability. With a planar-assembly nanofactory, almost any shape can be made as easily as any other, because the shapes are made by adding sub-micron nanoblocks to selected locations in a supported plane of the growing product. There will be less constraint on form than there is in sand casting of metals, and of course far more precision. This also means that what is built can contain functional components incorporated in the structure. Rather than building a frame and mounting other pieces later, the frame can be built with all components installed, forming a complete product. This does require functional joints between nanoblocks, but this is a small price to pay for such flexibility.

To specify functionality of a product, in many cases it will be sufficient to describe the desired functionality in the abstract without worrying about its physical implementation. If every cubic millimeter of the product contains a networked computer — which is quite possible, and may be the default — then to send a signal from point A to point B requires no more than specifying the points. Distributing energy or even transporting materials may not require much more attention: a rapidly rotating diamond shaft can transport more than a watt per square micron, and would be small enough to route automatically through almost any structure; pipes can be made significantly smaller if they are configured with continually inverting liners to reduce drag.

Thus, to design the acceleration and braking behavior of the motorcycle, it might be enough to specify the desired torque on the wheels as a function of speed, tire skidding, and brake and throttle position. A spreadsheet-like interface could calculate the necessary power and force for the motors, and from that derive the necessary axle thickness. The battery would be fairly massive, so the user would position it, but might not have to worry about the motor-battery connection, and certainly should not have to design the motor controller.

In order to include high-functionality materials such as motor arrays or stress-reporting materials, it would be necessary to start with a library of well-characterized "virtual materials" with standard functionality. This approach could significantly reduce the functional density of the virtual material compared to what would be possible with a custom-designed solution, but this would be acceptable for many applications, because functional density of nano-built equipment may be anywhere from six to eighteen orders of magnitude better than today's equipment. Virtual materials could also be used to specify material properties such as density and elasticity over a wide range, or implement active materials that changed attributes such as color or shape under software control.

Prototypes as well as consumer products could be heavily instrumented, warning of unexpected operating conditions such as excessive stress or wear on any part. Rather than careful calculations to determine the tradeoff between weight and strength, it might be better to build a first-guess model, try it on increasingly rough roads at increasingly high speeds, and measure rather than calculate the required strength. Once some parameters had been determined, a new version could be spreadsheeted and built in an hour or so at low cost. It would be unnecessary to trade time for money by doing careful calculations to minimize the number of prototypes. Then, for a low-performance application like a motorcycle, the final product could be built ten times stronger than was thought to be necessary without sacrificing much mass or cost.

There are only a few sources of shape requirements. One is geometrical: round things roll, flat things stack, and triangles make good trusses. These shapes tend to be simple to specify, though some applications like fluid handling can require intricate curves. The second source of shape is compatibility with other shapes, as in a piece that must fit snugly to another piece. These shapes can frequently be input from existing databases or scanned from an existing object. A third source of shape is user preference. A look at the shapes of pen barrels, door handles, and eyeglasses shows that users are pleased by some pretty idiosyncratic shapes.

To input arbitrary shapes into the blueprint, it may be useful to have some kind of interface that implements or simulates a moldable material like clay or taffy. A blob could simply be molded or stretched into a pleasing shape. Another useful technique could be to present the designer or user with several variations on a theme, let them select the best one, and build new variations on that until a sufficiently pleasing version is produced.

Although there is more to product design than the inputs described here, this should give some flavor of how much more convenient it could be with computer-controlled rapid prototyping of complete products. Elegant computer-input devices, pervasive instrumentation and signal processing, virtual material libraries, inexpensive creation of one-off spreadsheeted prototypes, and several other techniques could make product design more like a combination of graphic arts and computer programming than the complex, slow, and expensive process it is today.

* * * * * * * * * * * * * * * *

FUNDRAISING ALERT!


Recent developments in efforts to roadmap the technological steps towards molecular manufacturing make the work of CRN even more important.

It is critical that we examine the global implications of this rapidly emerging technology, and begin designing wise and effective policy. That's why we have formed the CRN Task Force.

But it won't be easy. We need to grow, and rapidly, to meet the expanding challenge.

Your donation to CRN will help us to achieve that growth. We rely largely on individual donations and small grants for our survival.

To make a contribution on-line, click here. This is important work and we welcome your participation!

* * * * * * * * * * * * * * * *

 

C-R-Newsletter #32    July 14, 2005

Nanotech Roadmap Initiative
New Nano Movie
Russian CRN Site Online
Nanotech Q&A for Russia
Nano-techno-logy
State of the Future 2005
Nanotechnology Workshop Webcast
CRN goes to Chicago
Feature Essay: Fast Development of Nano-Manufactured Products
FUNDRAISING ALERT!

=========

Things are moving very quickly throughout the nano-world and at CRN. We’ll recap some of the highlights here — but to keep up with the latest developments, be sure to check our Responsible Nanotechnology weblog. Thanks!


Nanotech Roadmap Initiative

Foresight Nanotech Institute, in cooperation with Battelle, a global research organization, has announced its intent to develop a "Technology Roadmap for Productive Nanosystems." CRN strongly encourages a cooperative program to map all the steps that will lead to molecular manufacturing. We have even outlined a series of studies that could go a long way toward meeting this goal. A combined effort — involving business, government, academic, and nonprofit participants — appears safest to us. This is especially true if numerous international partners are included, the more the better.

In principle, we support the idea of a collaborative technical roadmap project. It's not yet clear, however, if the Foresight announcement meets our description. We look forward to hearing more about it in the near future.


New Nano Movie

A new "must-see" short film has been produced using computer animation to assist in visualizing nanosystems and molecular manufacturing. Productive Nanosystems: from Molecules to Superproducts, is a collaborative effort of animator and engineer John Burch and pioneer nanotechnologist Dr. K. Eric Drexler, made possible through a challenge grant from Mark Sims and NanoRex. The four-minute film depicts an animated view of a nanofactory and demonstrates key steps in a process that converts simple molecules into a billion-CPU laptop computer. The movie file is 60+ MB. It will take a while to download, but it's definitely worth it.


Russian CRN Site Online

CRN is very pleased to announce that several pages from our main website have been translated into the Russian language and are posted on the Internet. Denis Tarasov, a Research Scientist in the Biology Department of Kazan State University in Russia, did most of the translation work. We are grateful for his assistance.

We now have CRN web pages available in five languages: English, Chinese, Spanish, Portuguese, and Russian. If you think you can help with other languages, please let us know.


Nanotech Q&A for Russia

Last month, NanoNewsNet, a web portal for nanotechnology news and research in Russia, interviewed CRN Executive Director Mike Treder for their site. The interview is posted online in the Russian language. We have an English translation here.


Nano-techno-logy

Three Greek words — nano (dwarf or tiny), techne (craft or skill), and logos (science or learning) — combine to make nano-techno-logy: applying science at a tiny scale to the craft or skill of building. Miracle predictions about nanotech's potential are common, as are dire warnings about the technology's risks. So, are the pessimists or the optimists right?

To find out, read this new essay by Mike Treder, published by Future Brief.


State of the Future 2005

Many people still do not appreciate how fast science and technology will change over the next 25 years, and given this rapid development along several different fronts, the possibility of technology growing beyond human control must now be taken seriously, according to a new report produced by the United Nations University's Millennium Project.

State of the Future 2005 analyzes current global trends and examines in detail some of the present and future challenges facing the world. As a consultant to the UN University's Millennium Project, CRN’s Mike Treder was involved with developing some of the findings contained in the report.


Nanotechnology Workshop Webcast

The Terasem Movement, Inc., a non-profit foundation focused on geoethical nanotechnology, has announced that an interactive webcast featuring Ray Kurzweil, Frank Tipler, James Hughes, Max More, Doug Mulhall, Mike Treder and others at its Geoethical Nanotechnology Workshop will be openly accessible from 8AM-6PM EST on Wednesday, July 20th.

Viewers of the interactive webcast are invited to email or IM (instant-message) questions directed to the presenters throughout the meeting. Each hour, some of these will be selected for the featured speakers to answer. The webcast will feature simultaneous transmission of audio, video, and PowerPoint presentations.

Geoethical nanotechnology is the development and implementation under a global regulatory framework of machines capable of assembling molecules into a wide variety of objects, in a broad range of sizes, and in potentially vast quantities.


CRN goes to Chicago

CRN's Mike Treder is speaking at two events in Chicago later this month. On Friday, July 29, at a special Symposium on Nanotechnology [PDF], Mike will deliver a presentation called "The Flat Horizon Problem: Nanotechnology on an Upward Slope."

The next day, Saturday, July 30, during the annual conference of the World Future Society, Mike is giving a talk titled, "Do Sweat the Small Stuff: Why Everyone Should Care About Nanotechnology." The conference, WorldFuture 2005: Foresight, Innovation, and Strategy, is at the Chicago Hilton and Towers. If you're going to be there, make sure to say hello to Mike.


Feature Essay: Fast Development of Nano-Manufactured Products
Chris Phoenix, Director of Research, Center for Responsible Nanotechnology

The extremely high performance of the products of molecular manufacturing will make the technology transformative—but it is the potential for fast development that will make it truly disruptive. If it took decades of research to produce breakthrough products, we would have time to adjust. But if breakthrough products can be developed quickly, their effects can pile up too quickly to allow wise policymaking or adjustment. As if that weren't bad enough, the anticipation of rapid development could cause additional problems.

How quick is "quickly?" Given a programmable factory that can make a product from its design file in a few hours, a designer could create a newly improved version every day. Today, building prototypes of a product can take weeks, so designers have to take extra time to double-check their work. If building a prototype takes less than a day, it will often be more efficient to build and test the product rather than taking time to double-check the theoretical design. (Of course, if taken to extremes, this can encourage sloppy work that costs more time to fix in the long run.)

In addition to being faster, prototyping also would be far cheaper. A nanofactory would go through the same automated operations for a single prototype copy as for a production run, so the prototype should cost no more per unit than the final product. That's quite a contrast with today, where rapid prototyping can cost thousands of dollars per component. And it means that destructive testing will be far less painful. Let's take an example. Today, a research rocket might cost hundreds of dollars to fuel, but hundreds of thousands to build. At that rate, tests must be held to a minimum number, and expensive and time-consuming efforts must be made to eliminate all possible sources of failure and gather as much data as possible from each test. But if the rocket cost only hundreds of dollars to build—if a test flight cost less than $1000, not counting support infrastructure—then tests could be run as often as convenient, requiring far less support infrastructure, saving costs there as well. The savings ripple out: with less at stake in every test, designers could use more advanced and less well-proved technologies, some of which would fail but others of which would increase performance. Not only would the product be developed faster, but it also would be more advanced, and have a lot more testing.

The equivalence between prototype and production manufacturing has an additional benefit. Today, products must be designed for two different manufacturing processes—prototyping and scaled-up production. Ramping up production has its own costs, such as rearranging production lines and training workers. But with direct-from-blueprint building, there would be no need to keep two designs in mind, and also no need to expend time and money ramping up production. When a design was finalized, it could immediately be shipped to as many nanofactories as desired, to be built efficiently and almost immediately. (For those just joining us, the reason nanofactories aren't scarce is that a nanofactory would be able to build another nanofactory on command, needing only data and supplies of a few refined chemicals.) A product design isn't really proved until people buy it, and rolling out a new product is expensive and risky today—after manufacture, the product must be shipped and stored in quantity, waiting for people to buy it. With last-minute nanofactory manufacturing, the product rollout cost could be much lower, reducing the overhead and risk of market-testing new ideas.

There are several other technical reasons why products could be easier to design. Today's products are often crammed full of functionality, causing severe headaches for designers trying to make one more thing fit inside the package. Anyone who's looked under the hood of a 1960 station wagon and compared it with a modern car's engine, or studied the way chips and wires are packed into every last nook and cranny of a cell phone, knows how crowded products can get. But molecular manufactured products will be many orders of magnitude more compact; this is true for sensors, actuators, data processing, energy transformation, and even physical structure. What this means is that any human-scale product will be almost entirely empty space. Designers will be able to include functions without worrying much about where they will physically fit into the product. This ability to focus on function will simplify the designer's task.

The high performance of molecularly precise nanosystems also means that designers can afford to waste a fair amount of performance in order to simplify the design. For example, instead of using a different size of motor for every different-sized task, designers might choose from only two or three standard sizes that might differ from each other by an order of magnitude or more. In today's products, using a thousand-watt motor to do a hundred-watt motor's job would be costly, heavy, bulky, and probably an inefficient use of energy besides. But nano-built motors have been calculated to be at least a million times as powerful. That thousand-watt motor would shrink to the size of a grain of sand. Running it at low power would not hurt its efficiency, and it wouldn't be in danger of overheating. It wouldn't cost significantly more to build than a carefully-sized hundred-watt motor. And at that size, it could be placed wherever in the product was most convenient for the designer.

Another potential advantage of having more performance than needed is that design can be performed in stages. Instead of planning an entire product at once, integrated from top to bottom, designers could cobble together a product from a menu of lower-level solutions that were already designed and understood. For example, instead of a complicated system with lots of custom hardware to be individually specified, designers could find off-the-shelf modules that had more features than required, string them together, and tweak their specifications or programming to configure their functionality to the needed product—leaving a lot of other functionality unused. Like the larger-than-necessary motor, this approach would include a lot of extra stuff that was put in simply to save the designer's time; however, including all that extra stuff would cost almost nothing. This approach is used today in computers. A modern computer spends at least 99% of its time and energy on retroactively saving time for its designers. In other words, the design is horrendously inefficient, but because computer hardware is so extremely fast, it's better to use trillions of extra calculations than to pay the designer even $10 to spend time on making the program more efficient. A modern personal computer does trillions of calculations in a fraction of an hour.

Modular design depends on predictable modules—things that work exactly as expected, at least within the range of conditions they are used in. This is certainly true in computers. It will also be true in molecular manufacturing, thanks to the digital nature of covalent bonds. Each copy of a design that has the same bond patterns between the atoms will have identical behavior. What this means is that once a modular design is characterized, designers can be quite confident that all subsequent copies of the design will be identical and predictable. (Advanced readers will note that isotopes can make a difference in a few cases, but isotope number is also discrete and isotopes can be sorted fairly easily as necessary to build sensitive designs. Also, although radiation damage can wipe out a module, straightforward redundancy algorithms will take care of that problem.)

With all these advantages, development of nano-built products, at least to the point of competing with today's products, appears to be easier in some important ways than was development of today's products. It's worth spending some thought on the implications of that. What if the military could test-fire a new missile or rocket every day until they got it right? How fast would the strategic balance of power shift, and what is the chance that the mere possibility of such a shift could lead to pre-emptive military strikes? What if doctors could build new implanted sensor arrays as fast as they could find things to monitor, and then use the results to track the effects of experimental treatments (also nano-built rapid-prototyped technology) before they had a chance to cause serious injury? Would this enable doctors to be more aggressive—and simultaneously safer—in developing new lifesaving treatments? If new versions of popular consumer products came out every month—or even every week—and consumers were urged to trade up at every opportunity, what are the environmental implications? What if an arms race developed between nations, or between police and criminals? What if products of high personal desirability and low social desirability were being created right and left, too quickly for society to respond? A technical essay is not the best place to get into these questions, but these issues and more are directly raised by the possibility that molecular manufacturing nanofactories will open the door to true rapid prototyping.


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FUNDRAISING ALERT!


Recent developments in efforts to roadmap the technological steps towards molecular manufacturing make the work of CRN even more important.

It is critical that we examine the global implications of this rapidly emerging technology, and CRN continues to be in the forefront of this discussion.

But we need to grow, and rapidly, to meet the expanding need.

Your donation to CRN will help us to achieve that growth. We rely largely on individual donations and small grants for our survival.

To make a contribution on-line, click here. This is important work and we welcome your participation!

* * * * * * * * * * * * * * * *

 

C-R-Newsletter #31    June 10, 2005

NanoWorld Weapons Warning
Citizen Conferences on Technology
CRN Policy Debate
Nanofuture: What's Next for Nanotechnology
CRN goes to Baltimore
Russian Translation Coming Soon
Reminder about Symposium on Nanotechnology
Feature Essay: Sudden Development of Molecular Manufacturing
FUNDRAISING ALERT!

=========

Even more than usual, things are happening fast at CRN. We'll recap some of the highlights here—but to keep up with the latest developments, be sure to check our Responsible Nanotechnology weblog.


NanoWorld Weapons Warning

"Nano could lead to new WMDs"

Does that sound like one of CRN's warnings? Not this time. It's the headline on a recent UPI article by Charles Choi, in which he interviews scientists from the University of Mexico and the University of California.

The scary thing is that they aren't focusing on advanced nanotechnology -- destructive new devices produced in mass quantity with molecular manufacturing -- because they don't have to. They make a convincing point just talking about improved (is that the right word?) chemical and biological weapons.

Already we're hearing sabers rattle and drums beat with the proposed weaponization of space. From there, it's a short step to military use of molecular machine systems with exponential manufacturing potential -- and at that point we're right on the edge of a very steep cliff.


Citizen Conferences on Technology

An innovative way to "stimulate broad and intelligent social debate on technological issues," pioneered in the 1980s by the Danish Board of Technology, is now getting underway in the UK, with a focus on nanotechnology.

We think this is a good sign. Public involvement in determining safe development and responsible use of advanced nanotechnology will be vital. CRN research suggests that these issues are likely to arise sooner than many expect. The surest way to avoid the worst dangers is to understand them in advance and take assertive action to prevent them.


CRN Policy Debate

After reading Executive Director Mike Treder's essay on "War, Interdependence, and Nanotechnology," C-R-Network member Steve Burgess engaged Mike in a friendly email 'debate' on nanotechnology policy. The discussion revolved around instituting fair distribution of nanotech-produced abundance as a way of preventing an uncontrollable arms race.

Issues covered were: 1) How can such distribution be imposed with a minimum of force and conflict? 2) Is it even ethical to attempt to impose a global system of abundance, superseding national sovereignties? 3) Even if the basis for a society based on lack of scarcity exists in the future, will evolved human psychology be able to make the transition without widespread fighting?

We posted the back and forth responses on our blog.


Nanofuture: What's Next for Nanotechnology

Flying cars, space travel for everyone, the elimination of poverty and hunger, and powerful new tools to combat disease, and even aging. These are some of the amazing predicted developments of nanotechnology, the coming science of designing and building machines at the molecular and atomic levels. Will this new scientific revolution be for better or worse?

That's from the publisher's description of Nanofuture: What's Next for Nanotechnology, a new nonfiction book by Dr. J. Storrs (Josh) Hall. We haven't read it yet, but based on the description and the rave reviews, this looks like a must-read. We wish Josh great success with his book.


CRN goes to Baltimore

About 50 engineers and other interested people attended an Emerging Technologies Forum titled "The Next Industrial Revolution: Molecular Nanotechnology and Manufacturing" in Baltimore last week. CRN Executive Director Mike Treder was asked to moderate the event, which was sponsored by the Society of Manufacturing Engineers (SME). Speakers included Scott Mize, president of the Foresight Institute, Dr. Joseph Jacobson from the Center for Bits and Atoms at MIT, Kevin Lyons of the National Science Foundation, Dr. Dennis Swyt of the NIST, and Dr. Richard Colton from the U.S. Naval Research Laboratory.

This forum was the second in a series intended to educate the manufacturing sector about what they can expect from advanced nanotechnology. CRN's Chris Phoenix spoke at the first event, which was last month in Minneapolis, Minnesota. We applaud SME for being forward-looking and helping to prepare their members for the next industrial revolution.


Russian Translation Coming Soon

We are excited to announce that a volunteer is translating several of CRN's web pages into the Russian language. Other volunteers from Russia’s Nanotechnology News Network are helping to edit and verify the translation.

When this is completed, we will have CRN web pages in Chinese, Spanish, Portuguese, and Russian, in addition to English. Next, we'll be looking for people to help with translations into Arabic, Bengali, French, German, Hindi, Japanese, and perhaps other languages. We want everyone to learn about responsible nanotechnology!


Reminder about Symposium on Nanotechnology

In connection with their hugely popular annual conference, the World Future Society has announced "an exploration series designed to provide an outline of several critical new fields with the potential for significant impact on the social, economic, and cultural fabric of modern society." For this year, they have organized a Symposium on Nanotechnology [PDF], which CRN's Mike Treder will assist in presenting. It's happening in Chicago on July 29, 2005. Hope to see you there!


Feature Essay: Sudden Development of Molecular Manufacturing
Chris Phoenix, Director of Research, Center for Responsible Nanotechnology

Development of molecular manufacturing technology probably will not be gradual, and will not allow time to react to incremental improvements. It is often assumed that development must be gradual, but there are several points at which minor improvements to the technology will cause massive advances in capability. In other words, at some points, the capability of the technology can advance substantially without breakthroughs or even much R&D. These jumps in capability could happen quite close together, given the pre-design that a well-planned development program would certainly do. Advancing from laboratory demos all the way to megatons of easily designed, highly advanced products in a matter of months appears possible. Any policy that will be needed to deal with the implications of such products must be in place before the advances start.

The first jump in capability is exponential manufacturing. If a manufacturing system can build an identical copy, then the number of systems, and their mass and productivity, can grow quite rapidly. However, the starting point is quite small; the first device may be one million-billionth of a gram (100 nanometers). It will take time for even exponential growth to produce a gram of manufacturing systems. If a copy can be built in a week, then it will take about a year to make the first gram. A better strategy will be to spend the next ten months in R&D to reduce the manufacturing time to one day, at which point it will take less than two months to make the first gram. And at that point, expanding from the first gram to the first ton will take only another three weeks.

It's worth pointing out here that nanoscale machinery is vastly more powerful than larger machinery. When a machine shrinks, its power density and functional density improve. Motors could be a million times more powerful than today's; computers could be billions of times more compact. So a ton of nano-built stuff is a lot more powerful than a ton of conventional product. Even though the products of tiny manufacturing systems will themselves be small, they will include computers and medical devices. A single kilogram of nanoscale computers would be far more powerful than the sum of all computers in existence today.

The second jump in capability is nanofactories—integrated manufacturing systems that can make large products with all the advantages of precise nanoscale machinery. It turns out that nanofactory design can be quite simple and scalable, meaning that it works the same regardless of the size. Given a manufacturing system that can make sub-micron blocks ("nanoblocks"), it doesn't take a lot of additional work to fasten those blocks together into a product. In fact, a product of any size can be assembled in a single plane, directly from blocks small enough to be built by single nanoscale manufacturing systems, because assembly speed increases as block size decreases. Essentially, a nanofactory is just a thin sheet of manufacturing systems fastened side by side. That sheet can be as large as desired without needing a re-design, and the low overhead means that a nanofactory can build its own mass almost as fast as a single manufacturing system. Once the smallest nanofactory has been built, kilogram-scale and ton-scale nanofactories can follow in a few weeks.

The third jump in capability is product design. If it required a triple Ph.D. in chemistry, physics, and engineering to design a nanofactory product, then the effects of nanofactories would be slow to develop. But if it required a triple Ph.D. in semiconductor physics, digital logic, and operating systems to write a computer program, the software industry would not exist. Computer programming is relatively easy because most of the complexity is hidden—encapsulated and abstracted within simple, elegant high-level commands. A computer programmer can invoke billions of operations with a single line of text. In the case of nanofactory product design, a good place to hide complexity is within the nanoblocks that are fastened together to make the product. A nanoblock designer might indeed need a triple Ph.D. However, a nanoblock can contain many millions of features—enough for motors, a CPU, programmable networking and connections, sensors, mechanical systems, and other high-level components.

Fastening a few types of nanoblocks together in various combinations could make a huge range of products. The product designer would not need to know how the nanoblocks worked—only what they did. A nanoblock is quite a bit smaller than a single human cell, and a planar-assembly nanofactory would impose few limits on how they were fastened together. Design of a product could be as simple as working with a CAD program to specify volumes to be filled and areas to be covered with different types of nanoblocks.

Because the internal design of nanoblocks would be hidden from the product designer, nanoblock designs could be changed or improved without requiring product designers to be retrained. Nanoblocks could be designed at a functional level even before the first nanofactory could be built, allowing product designers to be trained in advance. Similarly, a nanofactory could be designed in advance at the nanoblock level. Although simple design strategies will cost performance, scaling laws indicate that molecular-manufactured machinery will have performance to burn. Products that are revolutionary by today's standards, including the nanofactory itself, could be significantly less complex than either the software or the hardware that makes up a computer—even a 1970's-era computer.

The design of an exponential molecular manufacturing system will include many of the components of a nanofactory. The design of a nanofactory likewise will include components of a wide range of products. A project to achieve exponential molecular manufacturing would not need much additional effort to prepare for rapid creation of nanofactories and their highly advanced products.

Sudden availability of advanced products of all sizes in large quantity could be highly disruptive. It would confer a large military advantage on whoever got it first, even if only a few months ahead of the competition. This implies that molecular manufacturing technology could be the focus of a high-stakes arms race. Rapid design and production of products would upset traditional manufacturing and distribution. Nanofactories would be simple enough to be completely automated—and with components small enough that this would be necessary. Complete automation implies that they will be self-contained and easy to use. Nanofactory-built products, including nanofactories themselves, could be as hard to regulate as Internet file-sharing. These and other problems imply that wise policy, likely including some global-scale policy, will be needed to deal with molecular manufacturing. But if it takes only months to advance from 100-nanometer manufacturing systems to self-contained nanofactories and easily-designed revolutionary products, there will not be time to make wise policy once exponential manufacturing is achieved. We will have to start ahead of time.


* * * * * * * * * * * * * * * *

FUNDRAISING ALERT!

Recent developments in efforts to roadmap the technological steps towards molecular manufacturing make the work of CRN even more important.

It is critical that we examine the global implications of this rapidly emerging technology, and CRN continues to be in the forefront of this discussion.

But we need to grow, and rapidly, to meet the expanding need.

Your donation to CRN will help us to achieve that growth. We rely largely on individual donations and small grants for our survival.

To make a contribution on-line click here. This is important work and we welcome your participation.

* * * * * * * * * * * * * * * *

 

C-R-Newsletter #30    May 11, 2005

CRN goes to Minnesota
Moving Closer to a Manufacturing Revolution
War, Interdependence, and Nanotechnology
Nanotechnology Research Discrepancy?
Responsible Nanotechnology Report Issued
Reminder about WFS Seminar & Conference
Feature Essay: Molecular Manufacturing vs. Tiny Nanobots
CRN Needs Your Help!

=========

As usual, things are happening fast at CRN. We'll recap most of the highlights here—but to keep up with us on a daily basis, be sure to check our Responsible Nanotechnology weblog.
 

CRN goes to Minnesota

Last week, CRN Director of Research Chris Phoenix, made a presentation at a unique new conference sponsored by the Society of Manufacturing Engineers (SME). His talk, "Molecular Manufacturing: Beyond Nanomanufacturing," was based on a 50-page paper (see below) prepared especially for this event.

As far as we know, this is the first meeting ever presented by and for the manufacturing sector to focus specifically on what they can expect from advanced nanotechnology. The one-day conference, called "Molecular Nanotechnology and Manufacturing: The Enabling Tools and Applications," took place May 4 at the Minneapolis Convention Center.


Moving Closer to a Manufacturing Revolution

Nanotechnology’s long-expected transformation of manufacturing has just moved closer to reality. A new analysis of existing technological capabilities, including proposed steps from today's nanotech to advanced molecular machine systems, has been released by CRN.

The study, "Molecular Manufacturing: What, Why and How," was completed by Chris Phoenix and is available online at Wise-Nano.org. It shows how existing technologies can be coordinated toward a reachable goal of general-purpose molecular manufacturing.

Chris describes two approaches for building the initial basic tools with current technology. Other sections outline incremental improvement from those early tools toward the first integrated nanofactory, and analyze a scalable architecture for a more advanced nanofactory. Product performance and likely applications are discussed, as well as incentives for corporate or government investment in the technology. Finally, considerations and recommendations for a targeted development program are presented.


War, Interdependence, and Nanotechnology

From the dawn of the nuclear age until the present day, we have relied on two mechanisms to protect us from World War III: the doctrine of Mutually Assured Destruction (MAD), and the growing interdependence of nations. In the very near future, we may not be able to count on these controls. The tenuous balance of MAD and the worldwide network of commercial trade are both threatened by the rise of advanced nanotechnology.

"War, Interdependence, and Nanotechnology" is the title of a new essay from CRN Executive Director Mike Treder, published recently by Future Brief. The essay ends with a warning that the disruptive and destabilizing implications of advanced nanotechnology must not be underestimated. This is balanced, however, with recommendation for studies that may allow many of the near miraculous benefits to be realized without the worst-case disasters occurring.


Nanotechnology Research Discrepancy?

An important editorial in the current issue of The New Atlantis describes what they see as a "discrepancy between what Congress expects [from nanotechnology research] and what federal funds in fact support."

In reviewing the activities of a National Research Council committee tasked to evaluate the goals and progress of the U.S. National Nanotechnology Initiative, the editorial says...

It is our hope that the committee will offer a clear analysis of the technical potential of molecular manufacturing, and a clear recommendation on whether federal nanotechnology funds should be allocated toward theoretical and practical research into molecular manufacturing.

CRN believes that any serious, unbiased investigation into the steps required to move from today's nanoscale technologies to exponential general-purpose molecular manufacturing will conclude that the matter raises serious implications, and that actions heretofore ignored should be undertaken with urgency. By that, we mean a well-funded, dedicated program of inquiry something like our Thirty Essential Studies.

We hope the NRC committee will agree, and that their recommendation will spur similar—or, better yet, coordinated—actions from other major governmental and civil society organizations around the world.


Responsible Nanotechnology Report Issued

CRN's quarterly Responsible Nanotechnology Report has been delivered to members of the C-R-Network. Interested parties from 19 nations on six different continents received the report. Some of the countries include: Argentina, Australia, Belgium, Czech Republic, Egypt, Finland, France, India, Iran, Ireland, Nigeria, Russian Federation, Singapore, Taiwan, Thailand, and others, including the U.S., Canada, and the U.K.

If you would like to receive our quarterly report—in print, via email, or both—just sign up for the C-R-Network. It's free, and we welcome everyone's participation.


Reminder about WFS Seminar & Conference

In connection with their hugely popular annual conference, the World Future Society has announced "an exploration series designed to provide an outline of several critical new fields with the potential for significant impact on the social, economic, and cultural fabric of modern society." For this year, they have organized a Symposium on Nanotechnology (PDF), which CRN’s Mike Treder will assist in presenting. It’s happening in Chicago on July 29, 2005. Hope to see you there!


Feature Essay: Molecular Manufacturing vs. Tiny Nanobots
Chris Phoenix, Director of Research, Center for Responsible Nanotechnology

A few days ago, a high-ranking official of the National Nanotechnology Initiative told me that statements against "nanobots" on their website had been intended to argue against three-nanometer devices that could build anything.

This is frustrating, because no one has proposed such devices.

A three-nanometer cube would contain a few thousand atoms. This is about the right size for a single component, such as a switch or gear. No one has suggested building an entire robot in such a tiny volume. Even ribosomes, the protein-constructing machinery of cells, are more like 30 nanometers. A mechanical molecular fabrication system might be closer to 100 or 200 nanometers. That's still small enough to be built molecule-by-molecule in a few seconds, but large enough to contain thousands or millions of components.

Nanosystems a few hundred nanometers in size are convenient for several other reasons. They are small enough to be built error-free, and remain error-free for months or years despite background radiation. They are large enough to be handled mechanically with high efficiency and speed. They are smaller than a human cell. They are large enough to contain a complete CPU or other useful package of equipment. So it seems likely that designs for molecular manufacturing products and nanofactories will be based on components of this size.

So much for size. Let's look at the other half of that strawman, the part about "could build anything." There has been a persistent idea that molecular manufacturing proposes, and depends on, devices that can build any desired molecule. In fact, such devices have never been proposed. The idea probably comes from a misinterpretation of a section heading in Drexler's early book Engines of Creation.

The section in question talked about designing and building a variety of special-purpose devices to build special molecular structures: "Able to tolerate acid or vacuum, freezing or baking, depending on design, enzyme-like second-generation machines will be able to use as 'tools' almost any of the reactive molecules used by chemists -- but they will wield them with the precision of programmed machines. They will be able to bond atoms together in virtually any stable pattern, adding a few at a time to the surface of a workpiece until a complex structure is complete. Think of such nanomachines as assemblers."

Unfortunately, the section was titled "Universal Assemblers." This was misread as referring to a single "universal" assembler, rather than a collective capability of a large number of special-purpose machines. But there is not, and never was, any proposal for a single universal assembler. The phrase has always been plural.

The development of molecular manufacturing theory has in fact moved in the opposite direction. Instead of planning for systems that can do a very broad range of molecular fabrication, the latest designs aim to do just a few reactions. This will make it easier to develop the reactions and analyze the resulting structures.

Another persistent but incorrect idea that has attached itself to molecular manufacturing is the concept of "disassemblers." According to popular belief, tiny nanomachines will be able to take apart anything and turn it into raw materials. In fact, disassemblers, as described in Engines, have a far more mundane purpose: "Assemblers will help engineers synthesize things; their relatives, disassemblers, will help scientists and engineers analyze things." In other words, disassemblers are a research tool, not a source of feedstock.

Without universal assemblers and disassemblers, molecular manufacturing is actually pretty simple. Manufacturing systems built on a 100-nanometer scale would convert simple molecular feedstock into machine parts with fairly simple molecular structure—but, just as simple bricks can be used to build a wide variety of buildings, the simple molecular structure could serve as a backbone for rather intricate shapes. The manufacturing systems as well as their products would be built out of modules a few hundred nanometers in size. These modules would be fastened together to make large systems.

As I explained in my recent 50-page paper, "Molecular Manufacturing: What, Why, and How," recent advances in theory have shown that a planar layout for a nanofactory system can be scaled to any size, producing about a kilogram per square meter per hour. Since the factory would weigh about a kilogram per square meter, and could build a larger factory by extruding it edgewise, manufacturing capacity can be doubled and redoubled as often as desired. The implications of non-scarce and portable manufacturing capacity, as well as the high performance, rapid fabrication, and low cost of the products, are far beyond the scope of this essay. In fact, studying and preparing for these implications is the reason that CRN exists.


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CRN NEEDS YOUR HELP!

Since our founding two years ago, the Center for Responsible Nanotechnology has accomplished a great deal. We have published research papers, spoken at conferences, sent out press releases, and created a sizable presence on the web. As a result of these efforts, we have seen a considerable increase in awareness of the implications of advanced nanotechnology. This is vital work that few others are doing, despite its critical importance.

Unfortunately, we’re near the end of our current funding stream and virtually operating out of our own pockets. Unless we can quickly raise the funds necessary to support our growth, CRN's work will be severely hindered. If we are to continue, we need to aggressively seek other sources of funding, and that includes contributions from committed individuals such as yourself.

Please consider making a generous contribution to CRN. Your help, in any amount, will make a real difference to us in building the organization and continuing to inspire meaningful dialogue about our future in a world where molecular manufacturing is a reality.

To make a tax-deductible contribution by credit card, please
click here.

OR…you can mail a check, made out to "CRN/World Care" and addressed to:

CRN/World Care
PO Box 64001
Tucson, AZ  85728

Many thanks in advance for all the help you can give! Please feel free to contact us if you have any questions.

We sincerely appreciate the people who already have donated. You are truly making the world a better and safer place.

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C-R-Newsletter #29    April 14, 2005

New Research on DNA
Molecular Manufacturing, Step by Step
Nanotech High Beams
Information Week does CRN
Chris Phoenix Interviewed
Military Uses of Nanotechnology
CRN goes to San Diego
CRN goes to Minneapolis
Feature Essay: Protein Springs and Tattoo Needles—Work in progress at CRN
CRN Needs Your Help!

=========

It's been an extraordinarily busy and exciting month for CRN. We'll recap most of the highlights here—but to keep up with us on a daily basis, be sure to check our Responsible Nanotechnology weblog.
 

New Research on DNA

Inspired by one of CRN's Thirty Essential StudiesStudy #10, "What will be required to develop nucleic acid manufacturing and products?" — researcher Frank Boehm wrote "An Investigation of Nucleic Acid/DNA-Based Manufacturing." In a 26-page paper with 242 references, published online this month at the Wise-Nano.org website, Boehm describes many different kinds of tools in the DNA device toolbox, and shows how rapidly development is occurring in this field.


Molecular Manufacturing, Step by Step

Advanced nanotechnology—molecular manufacturing—will bring benefits and risks, both on an unprecedented scale. A new paper by Chris Phoenix, CRN's Director of Research, suggests that development of molecular manufacturing can be an incremental process from today's capabilities, and may not be as distant as many believe.

Three stages for the development of molecular manufacturing, each with specific milestones, are identified in the paper. The first stage is the computer-controlled fabrication of precise molecular structures. The second stage uses nanoscale tools to build more tools, enabling exponential growth of the manufacturing base. The third stage, which integrates nanoscale products into large structures, leads directly to desktop "nanofactories" that could build advanced products.


Nanotech High Beams

It’s as if we’re driving very fast, into pitch-black darkness, moving rapidly into uncharted territory… That's the state of nanotechnology today, argues CRN Executive Director Mike Treder in an essay published this month by Future Brief. The world's current lack of preparedness for the disruptive consequences of molecular manufacturing can only be redressed if we turn on the "high beams" and look further ahead. Examining the health and safety risks of current nanoscale technologies is necessary, but it is hardly sufficient.


Information Week does CRN

In March, Information Week published a news article about the "desktop nanofabrication system" (nanofactory) proposed by CRN's Chris Phoenix. The author, Chappell Brown, appropriately distinguished between the original vision of nanotechnology, and the relatively mundane—although highly useful—work being carried out today. The same story also appeared in EE Times. As a result of Brown's article, CRN's daily web traffic almost doubled.
 

Chris Phoenix Interviewed

In an in-depth interview published last month by nanomagazine, Chris answered many questions regarding nanofactory feasibility and the challenges that remain to develop the technology. This was actually the second segment of a long two-part interview; the first part is here. Thanks go to Sander Olson for his insightful questions and for publishing the full interview.
 

Military Uses of Nanotechnology

The final results of a six-month long study conducted by the people who run the Millennium Project of the American Council for the United Nations University were published last month. Two topics were covered: "Potential Environmental Pollution and Health Hazards Resulting from Possible Military Uses of Nanotechnology," and "Implications for Research Priorities Helpful to Prevent and/or Reduce Such Pollution and Hazards." An expert panel of 29 participants—including representation from CRN—identified potential military uses of nanotechnology that might occur between 2005–2010 and 2010–2025, and suggested research questions whose answers might produce knowledge to help prevent or reduce the health and environmental hazards. More details on the survey are available here.


CRN goes to San Diego

Mike was invited to make a presentation during a special "Nanotechnology and the Environment" symposium held in San Diego last month during the annual meeting of the American Chemical Society. Other speakers on the program were John Balbus of Environmental Defense, Christine Peterson of the Foresight Institute, and Alexis Vlandas of the International Network of Scientists and Engineers for Global Responsibility. The session was expertly organized by Barbara Karn and Nora Savage of the U.S. Environmental Protection Agency. A large audience seemed genuinely interested in what was presented and asked numerous questions about the longer-term implications of molecular manufacturing.


CRN goes to Minneapolis

Chris is scheduled to give a presentation next month at a conference sponsored by the Society of Manufacturing Engineers (SME). His talk, "Molecular Manufacturing: Beyond Nanomanufacturing," is based on a 50-page paper he has written especially for this conference, and which will be published in the official journal of conference proceedings. The one-day conference is called "Molecular Nanotechnology and Manufacturing: The Enabling Tools and Applications," and will take place at the Minneapolis Convention Center on May 4.


Feature Essay: Protein Springs and Tattoo Needles—Work in progress at CRN

Chris Phoenix, Director of Research, Center for Responsible Nanotechnology

This month's science essay will be a little different. Rather than explaining how a known aspect of the nanoscale works, I'll provide a description of my recent research activities and scientific thinking. I'll explain what the ideas are, where the inspirations came from, and what they might mean. This is a view "behind the scenes" of CRN. As always, I welcome comments and questions.

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I'm currently investigating two topics. One is how to make the simplest possible nanoscale molecular manufacturing system. I think I've devised a version that can be developed with today's technology, but can be improved incrementally to approach the tabletop diamondoid nanofactory that is the major milestone of molecular manufacturing. The other topic is how proteins work. I think I've had an insight that solves a major mystery: how protein machines can be so efficient. And if I'm right, it means that natural protein machines have inherent performance limitations relative to artificial machines.

I'll talk about the proteins first. Natural proteins can do things that we can't yet even begin to design into artificial proteins. And although we can imagine and even design machines that do equivalent functions using other materials, we can't build them yet. Although I personally don't expect proteins to be on the critical path to molecular manufacturing, some very smart people do, both within and outside the molecular manufacturing community. And in any case, I want to know how everything at the nanoscale works.

One of the major questions about protein machines is how they can be so efficient. Some of them, like ATP synthase, are nearly 100% efficient. ATP synthase has a fairly complex job: it has to move protons through a membrane, while simultaneously converting molecules of ADP to ATP. That's a pump and an enzyme-style chemical reaction--very different kinds of operation--linked together through a knobby floppy molecule, yet the system wastes almost no energy as it transfers forces and manipulates chemicals. A puzzle, to be sure: how can something like a twisted-up necklace of different-sized soft rubber balls be the building material for a highly sophisticated machine?

I've been thinking about that in the back of my mind for a few months. I do that a lot: file some interesting problem, and wait for some other random idea to come along and provide a seed of insight. This time, it worked. I have been thinking recently about entropy and springiness, and I've also been thinking about what makes a nanoscale machine efficient. And suddenly it all came together.

A nanoscale machine is efficient if its energy is balanced at each point in its action. In other words, if a motion is "downhill" (the machine has less energy at the end of the motion) then that energy must be transferred to something that can store it, or else it will be lost as heat. If a motion is "uphill" (requires energy) then that energy must be supplied from outside the machine. So a machine with large uphills and downhills in its energy-vs.-position trajectory will require a lot of power for the uphills, and will waste it on the downhills. A machine with sufficiently small uphills and downhills can be moved back and forth by random thermal motion, and in fact, many protein machines are moved this way.

A month or so ago, I read an article on ATP synthase in which the researchers claimed that the force must be constant over the trajectory, or the machine couldn't be efficient. I thought about it until I realized why this was true. So the question to be answered was, how was the force so perfectly balanced? I knew that proteins wiggled and rearranged quite a bit as they worked. How could such a seemingly ad-hoc system be perfectly balanced at each point along its trajectory?

As I said, I have been thinking recently about entropic springs. Entropy, in this application, means that nanoscale objects (including molecular fragments) like to have freedom to wiggle. A stringy molecule that is stretched straight will not be able to wiggle. Conversely, given some slack, the molecule will coil and twist. The more slack it has, the more different ways it can twist, and the happier it will be. Constraining these entropic wiggles, by stretching a string or squashing a blob, costs energy. At the molecular scale, this effect is large; it turns out that entropic springiness, and not covalent bond forces, is the main reason why latex rubber is springy. This means that any nanoscale wiggly thing can function as an entropic spring. I sometimes picture it as a tumbleweed with springy branches--except that there is only one object (for example, a stringy molecule) that wiggles randomly into all the different branch positions. Sometimes I compare it to a springy cotton ball.

One Saturday morning I happened to be thinking simultaneously about writhing proteins, entropic springs, and efficient machines. I suddenly realized, as I thought about the innards of a protein rearranging themselves like a nest of snakes, that installing lots of entropic springs in the middle of that complex environment would provide lots of adjustable parameters to balance whatever force the machine's function generated. Because of the complex structural rearrangement of the protein, each spring would affect a different fraction of the range of motion. Any uphills and downhills in its energy could be smoothed out.

Natural protein machines are covered and filled with floppy bits that have no obvious structural purpose. However, each of those bits is an entropic spring. As the machine twists and deforms, its various springs are compressed or allowed to expand. An entropic spring only has to be attached at one point; it will press against any surface that happens to come into its range. Compressing the spring takes energy and requires force; releasing the spring will recover the energy, driving the machine forward.

As soon as I had that picture, I realized that each entropic spring could be changed independently, by blind evolution. By simply changing the size of the molecule, its springiness would be modified. If a change in a spring increased the efficiency of the machine, it would be kept. The interior reconfiguration of proteins would provide plenty of different environments for the springs--plenty of different variables for evolution to tweak.

Always before, when I had thought about trying to design a protein for efficiency and effectiveness, I had thought about its backbone--the molecular chain that folds up to form the structure. This is large, clumsy, and soft--not suitable for implementing subtle energy balancing. It would be very hard (no pun intended) to design a system of trusses, using protein backbones and their folded structure, that could implement the right stiffness and springiness to balance the energy in a complex trajectory. But the protein's backbone has lots of dangling bits attached. The realization that each of those was an entropic spring, and each could be individually tuned to adjust the protein's energy at a different position, made the design task suddenly seem easy.

The task could be approached as: 1) Build a structure to perform the protein's function without worrying about efficiency and energy balance. Make it a large structure with a fair amount of internal reconfiguration (different parts having different relative orientations at different points in the machine's motion); 2) Attach lots of entropic springs all over the structure; 3) Tune the springs by trial and error until the machine is efficient--until the energy stored by pressure on the myriad springs exactly balances the energy fluctuations that result from the machine's functioning.

I proposed this idea to a couple of expert nanoscale scientists--a molecular manufacturing theorist and a physicist. And I learned a lot. One of the experts said that he had not previously seen the observation that adding lots of springs made it easier to fine-tune the energy accurately. That was pretty exciting. I learned that proteins do not usually disfigure themselves wildly during their operation--interior parts usually just slip past each other a bit. I watched some movies of proteins in action, and saw that they still seemed to have enough internal structural variation to cause different springs to affect different regions of the motion trajectory. So, that part of the idea still seems right.

I had originally been thinking in terms of the need to balance forces; I learned that energy is a slightly more general way to think about the problem. But in systems like these, force is a simple function of energy, and my theory translated perfectly well into a viewpoint in terms of energy. It turned out that one of my experts had studied genetic algorithms, and he warned that there is no benefit to increasing the number of evolvable variables in the system if the number of constraints increases by the same number. I hadn't expected that, and it will take more theoretical work to verify that adding extra structures in order to stick more entropic springs on them is not a zero-sum game. But my preliminary thinking says that one piece of structure can have lots of springs, so adding extra structures is still a win.

The other expert, the physicist, asked me how much of the effect comes from entropic springiness vs. mechanical springiness. That's a very good question. I realized that there is a measurable difference between entropic springs and mechanical (covalent bond) springs: the energy stored by an entropic spring is directly proportional to the temperature. If a machine's efficiency depends on fine-tuning of entropic springs, then changing the temperature should change all the spring constants and destroy the delicate energy balance that makes it efficient. I made the prediction, therefore, that protein machines would have a narrow temperature range in which they would be efficient. Then I thought a bit more and modified this. A machine could use a big entropic spring as a thermostat, forcing itself into different internal configurations at each temperature, and fine-tuning each configuration separately. This means that a machine with temperature-sensitive springs could evolve to be insensitive to temperature. But a machine that evolved at a constant temperature, without this evolutionary pressure, should be quite sensitive to temperature.

After thinking this through, I did a quick web search for the effect of temperature on protein activity. I quickly found a page containing a sketch of enzyme activity vs. temperature for various enzymes. Guess what--the enzyme representing Arctic shrimp has maximum activity around 4 C, and mostly stops working just a few degrees higher. That looks like confirmation of my theory.

That web page, as well as another one, says that enzymes stop working at elevated temperatures due to denaturation--change in three-dimensional structure brought on by breaking of weak bonds in the protein. The other web page also asserts that the rate of enzyme activity, "like all reactions," is governed by the Arrhenius equation, at least up to the point where the enzyme starts to denature. The Arrhenius equation says that if an action requires thermal motion to jump across an energy barrier, the rate of the action increases as a simple exponential function of temperature. But this assumes that the height of the barrier is not dependent on temperature. If the maintenance of a constant energy level (low barriers) over the range of the enzyme's motion requires finely tuned, temperature dependent mechanisms, then spoiling the tuning--by a temperature change in either direction--will decrease the enzyme's rate.

I'll go out on a limb and make a testable prediction. I predict that many enzymes that are evolved for operation in constant or nearly constant temperature will have rapid decrease of activity at higher and lower temperatures, even without structural changes. When the physical structure of some of these supposedly denatured enzymes is examined, it will be found that the enzyme is not in fact denatured: its physical structure will be largely unchanged. What will be changed is the springiness of its entropic springs.

If I am right about this, there are several consequences. First, it appears that the design of efficient protein machines may be easier than is currently believed. There's no need to design a finely-tuned structure (backbone). Design a structure that barely works, fill it with entropic springs, and fine-tune the springs by simple evolution. Analysis of existing proteins may also become easier. The Arrhenius equation should not apply to a protein that uses entropic springs for energy balancing. If Arrhenius is being misapplied, then permission to stop using it and fudging numbers to fit around it should make protein function easier to analyze. (The fact that 'everyone knows' Arrhenius applies indicates that, if I am right about entropic springs being used to balance energy, I've probably discovered something new.)

Second, it may imply that much of the size and intricate reconfiguration of protein machines exists simply to provide space for enough entropic springs to allow evolutionary fine-tuning of the system. An engineered system made of stiff materials could perform an equivalent function with equivalent efficiency by using a much simpler method of force/energy compensation. For example, linking an unbalanced system to an engineered cam that moves relative to a mechanical spring will work just fine. The compression of the spring, and the height of the cam, will correspond directly to the energy being stored, so the energy required to balance the machine will directly specify the physical parameters of the cam.

The third consequence, if it turns out that protein machines depend on entropic springs, is that their speed will be limited. To be properly springy, an entropic spring has to equalize with its space; it has to have time to spread out and explore its range of motion. If the machine is moved too quickly, its springs will lose their springiness and will no longer compensate for the forces; the machine will become rapidly less efficient. Stiff mechanical springs, having fewer low-frequency degrees of freedom, can equilibrate much faster. If I understand correctly, my physics expert says that a typical small entropic spring can equilibrate in fractions of a microsecond. But stiff mechanical nanoscale springs can equilibrate in fractions of a nanosecond.

I will continue researching this. If my idea turns out to be wrong, then I will post a correction notice in our newsletter archive at the top of this article, and a retraction in the next newsletter. But if my idea is right, then it appears that natural protein machines must have substantially lower speeds than engineered nanoscale machines can achieve with the same efficiency. "Soft" and "hard" machines do indeed work differently, and the "hard" machines are simply better.

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The second thing I am investigating is the design of a nanoscale molecular manufacturing system that is simple enough to be developed today, but functional enough to build rapidly improving versions and large-throughput arrays.

It may seem odd, given the ominous things CRN has said about the dangers of advanced molecular manufacturing, that I am working on something that could accelerate it. But there's a method to my madness. Our overall goal is not to retard molecular manufacturing; rather, it is to maximize the amount of thought and preparation that is done before it is developed. Currently, many people think molecular manufacturing is impossible, or at least extremely difficult, and will not even start being developed for many years. But we believe that this is not true--we’re concerned that a small group of smart people could figure out ways to develop basic capabilities fairly quickly.

The primary insights of molecular manufacturing--that stiff molecules make good building blocks, that nanoscale machines can have extremely high performance, and that general-purpose manufacturing enables rapid development of better manufacturing systems--have been published for decades. Once even a few people understand what can be done with even basic capabilities, we think they will start working to develop them. If most people do not understand the implications, they will be unprepared. By developing and publishing ways to develop molecular manufacturing more easily, I may hasten its development, but I also expect to improve general awareness that such development is possible and may happen surprisingly soon. This is a necessary precondition for preparedness. That's why I spend a lot of my time trying to identify ways to develop molecular manufacturing more easily.

An early goal of molecular manufacturing is to build a nanoscale machine that can be used to build more copies and better versions. This would answer nagging worries about the ability of molecular manufacturing systems to make large amounts of product, and would also enable rapid development of molecular manufacturing technologies leading to advanced nanofactories.

I've been looking for ways to simplify the Burch/Drexler planar assembly nanofactory. This method of "working backward" can be useful for planning a development pathway. If you set a plausible goal pretty far out, and then break it down into simpler steps until you get to something you can do today, then the sequence of plans forms a roadmap for how to get from today's capabilities to the end goal.

The first simplification I thought of was to have the factory place blocks that were built externally, rather than requiring it to manufacture the blocks internally. If the blocks can be prefabricated, then all the factory has to do is grab them and place them into the product in specified locations.

I went looking for ways to join prefabricated molecular blocks and found a possible solution. A couple of amino acids, cysteine and histidine, like to bind to zinc. If two of them are hooked to each block, with a zinc ion in the middle, they'll form a bond quite a bit stronger than a hydrogen bond. That seems useful, as long as you can keep the blocks from joining prematurely into a random lump. But you can do that simply by keeping zinc away.

So, mix up a feedstock with lots of molecular zinc-binding building blocks, but no zinc. Build a smart membrane with precisely spaced actuators in it that can transport blocks through the membrane. On one side of the membrane, put the feedstock solution. On the other side of the membrane, put a solution of zinc, and the product. As the blocks come through the membrane one at a time, they join up with the zinc and become "sticky"--but the mechanism can be used to retain them and force them into the right place in the product. It shouldn't require a very complex mechanism to "grab" blocks from feedstock (via Brownian assembly) through a hole in a membrane, move them a few nanometers to face the product, and stick them in place. In fact, it should be possible to do this with just one molecular actuator per position. A larger actuator can be used to move the whole network around.

Then I thought back to some stuff I knew about how to keep blocks from clumping together in solution. If you put a charge on the blocks, they will attract a "screen" of counterions, and will not easily bump each other. So, it might be possible to keep blocks apart even if they would stick if they ever bumped into each other. In fact, it might be very simple. A zinc-binding attachment has four amino acids per zinc, two on each side. Zinc has a +2 charge. If the rest of the block has a -1 charge for every pair of amino acids, then when the block is bound with zinc into a product, all the charges will match up. But if it's floating in solution with zinc, then the zinc will still be attracted to the two amino acids; in this case, the block should have a positive charge, since each block will have twice as much zinc-charge associated with it in solution as when it's fastened into the product. This might be enough to keep blocks from getting close enough to bind together. But if blocks were physically pushed together, then the extra zinc would be squeezed out, and the blocks would bind into a very stable structure.

That's the theory, at this point. It implies that you don't need a membrane, just something like a tattoo needle that attaches blocks from solution and physically pushes them into the product. I do not know yet whether this will work. I will be proposing to investigate this as part of a Phase 2 NIAC project. If the theory doesn't work, there are several other ways to fasten blocks, some triggered by light, some by pressure, and some simply by being held in place for a long enough period of time.

It appears, then, that the simplest way to build a molecular manufacturing system may be to develop a set of molecular blocks that will float separately in solution but fasten together when pushed. At first, use a single kind of block, containing a fluorescent particle. Use a scanning probe microscope to push the blocks together. (You can scan the structure with the scanning probe microscope, or see the cluster of fluorescence with an ordinary light microscope.) Once you can build structures this way, build a structure that will perform the same function of grabbing blocks and holding them to be pushed into a product. Attach that structure to a nano-manipulator and use it to build more structures. You'd have a hard time finding the second-level structures with a scanning probe microscope, but again the cluster of fluorescence should show up just fine in a light microscope.

Once you know you can build a passive structure that builds structures when poked at a surface, the next step is to build an active structure--including an externally controlled nanoscale actuator--that builds structures. Use your scanning probe microscope with multiple block types to build an actuator that pushes its block forward. Build several of those in an array. Let them be controlled independently. You still need a large manipulator to move the array over the surface, but you can already start to increase your manufacturing throughput. By designing new block types, and new patterns of attaching the blocks together, better construction machines could be built. Sensors could be added to detect whether a block has been placed correctly. Nanoscale digital logic could be added to reduce the number of wires required to control the system. And if anyone can get this far, there should be no shortage of ideas and interest directed at getting farther.

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That's an inside look at how my thinking process works, how I develop ideas and check them with other experts, and how what I'm working on fits in with CRN's vision and mission. Please contact me if you have any feedback.

Chris

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CRN NEEDS YOUR HELP!

Since our founding two years ago, the Center for Responsible Nanotechnology has accomplished a great deal. We have published research papers, spoken at conferences, sent out press releases, and created a sizable presence on the web. As a result of these efforts, we have seen a considerable increase in awareness of the implications of advanced nanotechnology. This is vital work that few others are doing, despite its critical importance.

Unfortunately, we’re near the end of our current funding stream and virtually operating out of our own pockets. Unless we can quickly raise the funds necessary to support our growth, CRN's work will be severely hindered. If we are to continue, we need to aggressively seek other sources of funding, and that includes contributions from committed individuals such as you.

Please consider making a generous contribution to CRN. Your help, in any amount, will make a real difference to us in building the organization and continuing to inspire meaningful dialogue about our future in a world where molecular manufacturing is a reality.

To make a tax-deductible contribution by credit card, please
click here. You will be directed to World Care's page under "Network for Good." In the Designation box, be sure to say that your donation is for CRN.

OR…you can mail a check, made out to "CRN/World Care" and addressed to:

CRN/World Care
PO Box 64001
Tucson, AZ  85728

Many thanks in advance for all the help you can give! Please feel free to contact us if you have any questions.

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C-R-Newsletter #28    March 10, 2005

CONTENTS

CRN goes to Washington
CRN goes to Italy
SciDev.net addresses Nanotechnology
UK Government responds to Royal Society
CRN says "Nanobots Not Needed"
Talking with Economists about Nanotechnology
Talking with Chemists about Nanotechnology
Feature Essay: Information Delivery for Nanoscale Construction

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CRN goes to Washington

Last month (February 10-11), Chris Phoenix attended a two-day workshop in Washington D.C. organized by the U.S. National Academy of Sciences, and spoke on a panel of experts about the meaning of and potential for molecular manufacturing. Chris also was asked to prepare a series of briefing papers for the NAS committee, which have since been posted on our Responsible Nanotechnology weblog. The committee appeared to study the matter with an open mind, and we look forward to their first report to Congress this summer.


CRN goes to Italy

While Chris was in Washington, Mike Treder was in Trieste, Italy, taking part in an Expert Group Meeting on "North-South Dialog on Nanotechnology: Challenges and Opportunities." The meeting was organized by the International Centre for Science and High Technology, an Institute of the United Nations operating in the framework of the United Nations Industrial Development Organization.

A total of eighty people from all around the world—scientists, academics, government personnel, and NGO representatives—were gathered for this event. Mike presented his ideas on "Creating Effective Public Policy for Managing Advanced Nanotechnology," which was favorably received, although there were differing points of view on the expected time frame for development of molecular manufacturing. You can view Mike's PowerPoint presentation here.


SciDev.net addresses Nanotechnology

The online news site SciDev.net recently posted a "Nanotechnology Quick Guide," which includes an overview of both current nanoscale technologies and the possibilities of advanced nanotechnology. One of the links they provide is to CRN, and in fact, we were told by the Quick Guide’s primary author, Catherine Brahic, that she used our material as a resource for her writing.

SciDev.net also published an editorial entitled "Helping the poor: the real challenge of nanotech," commenting on the issues discussed at the Expert Group Meeting mentioned above.
 

UK Government responds to Royal Society

In 2003, the British government asked the Royal Society (somewhat equivalent to the U.S. National Academy of Sciences) to undertake a study on "nanotechnology and the health and safety, environmental, ethical and social issues that might stem from it." Their final report was issued on July 29, 2004.

The UK government finally got around to responding to the report’s findings just a few weeks ago, and no one, it seems, was pleased with what they said. Professor Ann Dowling, chair of the working group that produced the report, expressed disappointment, as did scientist and blogger Richard Jones, and eco-activist Jim Thomas of the ETC Group. CRN also spoke out about the government’s tepid response and the urgent need for more serious consideration of both the risks and benefits of nanotechnology.
 

CRN says "Nanobots Not Needed"

The popular idea of so-called nanobots, powerful and at risk of running wild, is not part of modern plans for building things "atom-by-atom" by molecular manufacturing. Studies indicate that most people don't know the difference between molecular manufacturing, nanoscale technology, and nanobots. Confusion about terms, fueled by science fiction, has distorted the truth about advanced nanotechnology. Nanobots are not needed for manufacturing, but continued misunderstanding may hinder research into highly beneficial technologies and discussion of the real dangers.

That's the summary of a new briefing document prepared by CRN and provided primarily for journalists and others who write or teach about nanotechnology.

As nanoscale technologies begin to move from the lab to the marketplace, and attention turns to molecular manufacturing research, it will be increasingly important to counter outdated and incorrect ideas of nanotechnology and molecular manufacturing. Both scientists and the public have gotten the idea that molecular manufacturing requires the use of nanobots, and they may criticize or fear it on that basis. The truth is less sensational, but its implications are equally compelling.

Our statement stimulated lively discussion on the Foresight Institute's nanodot site, Howard Lovy's blog, and the Google group sci.nanotech.
 

Talking with Economists about Nanotechnology

Mike was asked to serve as moderator for a panel discussion at the Eastern Economic Association Annual Conference in New York City last week. The panel was on "The Inevitability of BIG in a Robotic Future" (BIG is Basic Income Guarantee). During discussion after the panelist's presentations, the subject of economic disruption and other societal impacts resulting from molecular manufacturing was raised. So Mike had the opportunity to share some of CRN's concerns with a group of noted economists and sociologists.
 

Talking with Chemists about Nanotechnology

We received a last-minute invitation to speak at a "Nanotechnology and the Environment" symposium during the American Chemical Society's 2005 annual meeting. Mike will travel to San Diego, California, this weekend to deliver a short presentation on "the environmental, human health and societal aspects of nanotechnology." It won't be easy to adequately cover so many issues in a short address, but it's good to see that the ACS is taking our point of view seriously.
 

Feature Essay: Information Delivery for Nanoscale Construction
Chris Phoenix, Director of Research, CRN

A widely acknowledged goal of nanotechnology is to build intricate, useful nanoscale structures. What usually goes unstated is how the structures will be specified. Simple structures can be created easily: a crystal is an atomically precise structure that can be created from simple molecules and conditions. But complex nano-products will require some way to deliver large quantities of information to the nanoscale.

A key indicator of a technology's usefulness is how fast it can deliver information. A kilobyte is not very much information—less than a page of text or a thumbnail image. A dialup modem connection can transfer several kilobytes per second. Today's nanoscale manufacturing techniques can transfer at most a few kilobytes per second. This will not be enough to make advanced products—only simple materials or specialized components.

The amount of information needed to specify a product is not directly related to the size of the product. A product containing repetitive structures only needs enough information to specify one of the structures and control the placement of the rest. The amount of information that needs to be delivered also depends on whether the receiving machine must receive an individual instruction for every operation, or whether it can carry out a sequence of operations based on stored instructions. Thus, a primitive fabrication system may require a gigabyte of information to place a million atoms, while a gigabyte may be sufficient to specify a fairly simple kilogram-scale product built with an advanced nanofactory.

There are several ways to deliver information to the nanoscale so as to construct things. Information can either be encoded materially, in a stable pattern of atoms or electrons, or it can be in an ephemeral form such as an electric field, a pattern of light, a beam of charged particles, the position of a scanning probe, or an environmental condition like temperature. The goal of manufacturing is to embody the information, however it is delivered, into a material product. As we will see, different forms of delivery have different advantages and limitations.

Today's Techniques

To create a material pattern, it is tempting to start with materially encoded information. This is what self-assembly does. A molecule can be made so that it folds on itself or joins with others in quite intricate patterns. An example of this that is well understood, and has already been used to make nanoscale machines, is DNA. (See our previous science essay, "Nucleic Acid Engineering.") Biology uses DNA mainly to store information, but in the lab it has been used to make polyhedra, grid structures, and even a programmable machine that can synthesize DNA strands.

One problem with self-assembly is that all the information in the final structure must be encoded in the components. In order to make a complicated structure, a lot of information must be programmed into the component molecules. There are only a few ways to get information into molecules. One is to make the molecules a piece at a time. In a long linear chain like DNA, this can be done by repeating a few operations many times—specifically, by changing the chemical environment in a way that adds one selected block to the chain in each operation. (This can be viewed either as chemistry or as manufacturing.) Automated machines exist that will do this by cycling chemicals through a reactor, but they are relatively slow, and the process is expensive. The information rate can be greatly increased by controlling the process with light; by shining light in programmed sequence on different regions of a surface, DNA can be grown in many different patterns in parallel. This can create a large “library” of different DNA molecules with programmed sequences.

Another problem with self-assembly is that when the building blocks are mixed together, it is hard to impose long-range order and to build heterogeneous engineered structures. This limitation may be partially alleviated by providing a large-scale template, either a material structure or an ephemeral spatial pattern. Adding building blocks in a programmed sequence rather than mixing them all together all at once also may help. A combination of massively parallel programmable molecule synthesis and templated or sequenced self-assembly may be able to deliver kilobytes per second of information to the nanoscale.

A theoretical possibility should be mentioned here. Information can be created by starting with a lot of random codes, throwing away all the ones that don't work, and duplicating the ones that do. One problem with this is that for all but the simplest criteria, it will be too difficult and time-consuming to implement tests for the desired functionality. Another problem is that evolved solutions will require extra work to characterize, and unless characterized, they will be hard to integrate into engineered systems. Although evolution can produce systems of great subtlety and complexity, it is probably not suitable for producing easily characterized general-purpose functional modules. Specific molecular bio-designs such as molecular motors may be worth characterizing and using, but this will not help with the problem of controlling the construction of large, heterogeneous, information-rich products.

Optical lithography of semiconductors now has the capability to generate nanoscale structures. This technique creates a pattern of light using a mask. The light causes chemical changes in a thin surface layer; these changes can then be used to pattern a substrate by controlling the deposition or removal of material. One drawback of this approach is that it is not atomically precise, since the pattern of light is far too coarse to resolve individual atoms. Another drawback is that the masks are pre-built in a slow and very expensive process. A computer chip may embody billions of bytes of information, but the masks may take weeks to make and use; again, this limits the data rate to kilobytes per second. There has been recent talk of using MEMS (micro electro mechanical systems) technology to build programmable masks; if this works out, it could greatly increase the data rate.

Several tools can modify single points in serial fashion with atomic or near-atomic resolution. These include scanning probe microscopes and beams of charged particles. A scanning probe microscope uses a large but sensitive positioning and feedback system to bring a nanoscale point into controlled physical contact with the surface. Several thousand pixels can be imaged per second, so in theory an automated system could deliver kilobytes per second of changes to the surface. An electron beam or ion beam can be steered electronically, so it can be relatively fast. But the beam is not as precise as a scanning probe can be, and must work in vacuum. The beam can be used either to remove material, to chemically transform it, or to deposit any of several materials from low-pressure gas. It takes a fraction of a millisecond to make a shallow feature at a chosen point. Again, the information delivery rate is kilobytes per second.

Nanoscale Tools

To deliver information at a higher rate and use the information for more precise construction, new technology will be required. In most of the techniques surveyed above, the nanoscale matter is inert and is acted on by outside forces (ephemeral information) created by large machines. In self-assembly, the construction material itself encodes static patterns of information—which probably were created by large machines doing chemistry. By contrast, nanoscale tools, converting ephemeral information to concrete operations, could substantially improve the delivery rate of information for nanoscale construction. Large tools acting on inert nanoscale objects could never come close to the data rates that are theoretically possible with nanoscale tools.

One reason why nanoscale tools are better is that they can move faster. To a first approximation, the operating frequency of a tool increases in direct proportion as its linear size shrinks. A 100-nm tool should be about a million times faster than a 10-cm tool.

The next question is how the information will be delivered. There are several candidates for really fast information delivery. Light can be switched on and off very rapidly, but is difficult to focus tightly. Another problem is that absorption of light is probabilistic, so a lot of light would have to be used for reliable information delivery. Perhaps surprisingly, mechanical signals may be useful; megahertz vibrations and pressure waves can be sent over useful distances. Electrical signals can be sent along nanoscale wires so that multiple independent signals could be delivered to each tool. In principle, the mechanical and electrical portions of the system could be synchronized for high efficiency.

Nanoscale computing elements can help with information handling in two ways. First, they can split up a broadcast signal, allowing several machines receiving the same signal to operate independently. This can reduce the complexity of the macro-to-nano interface. Second, nanoscale computation can be used to implement some kinds of error handling at a local level.

A final advantage of nanoscale tools, at least the subset of tools built from molecules, is that they can be very precise. Precision is a serious problem in micron-sized tools. A structure built by lithography looks like it has been whittled with a pocket knife—the edges are quite ragged. This has made it very difficult to build complex, useful mechanical devices at the micron scale using lithography. Fortunately, things get precise again at the very bottom, because atoms are discrete and identical. Small and simple molecular tools have been built, and work is ongoing to build larger and more integrated systems. The structural precision of molecular tools promises several advantages, including predictable properties and low-friction interfaces.

Several approaches could be used, perhaps in combination, to build a nanoscale fabrication system. If a simple and repetitive system can be useful, then self-assembly might be used to build it. A repetitive system, once fabricated, might be made less repetitive (programmed heterogeneously) by spatial patterns such as an array of light. If it contains certain kinds of electronics, then signals could be sent in to uniquely reconfigure the circuitry in each repeating sub-pattern.

Of course, the point of the fabrication system is to build stuff, and a particularly interesting kind of system is one that can build larger or better fabrication systems. With information supplied from outside, a manufacturing system of this sort could build a larger and more complex version of itself. This approach is one of the goals of molecular manufacturing. It would allow the first tiny system to be built by a very expensive or non-scalable method, and then that tiny system can build larger ones, rapidly scaling upward and drastically reducing cost. Or if the initial system was built by self-assembly, then subsequent systems could be more complex than self-assembly could easily achieve.

The design of even a tabletop general-purpose manufacturing system could be relatively simple, heterogeneous but hierarchical and repetitive. Once the basic capabilities of nanoscale actuation, computation, and fabrication are achieved in a way that can be engineered and recombined, it may not take too long to start developing nanoscale tools that can do this in parallel, using computer-supplied blueprints to build larger manufacturing systems and a broad range of products.

C-R-Newsletter #27    February 3, 2005

CONTENTS

NAS Workshop
Expert Group Meeting
Network Activity Coordinator
Events Coordinator
Nano-Workshops
Symposium on Nanotechnology
New Paper Posted
Feature Essay: What Is Molecular Manufacturing?

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NAS Workshop

As part of the U.S. 21st Century Nanotechnology Research and Development Act (PDF), passed by Congress and signed into law by the President in December 2003, the National Academy of Sciences is required to "organize a workshop to study the technical feasibility of molecular self-assembly for the manufacture of materials and devices at the molecular scale."

That workshop is being held in Washington DC February 10-11, 2005. CRN’s Chris Phoenix has been appointed to a panel of experts that will address the NAS committee, and he will attend the entire workshop.


Expert Group Meeting

At the same time that Chris is in Washington, Mike Treder will be in Trieste, Italy, to take part in an Expert Group Meeting on "North-South dialog on nanotechnology: challenges and opportunities." The meeting is organized by the International Centre for Science and High Technology, an Institute of the United Nations operating in the framework of the United Nations Industrial Development Organization. This is quite an honor, and we are pleased to have the opportunity to contribute.


Network Activity Coordinator

We are pleased to announce the appointment of Martin Coppa to the position of CRN Network Activity Coordinator. In this volunteer role, he will promote opportunities for student research collaborations within educational networks, maintain up-to-date records of C-R-Network membership, and coordinate communication with Network members.

Martin, who lives in San Francisco, is an undergraduate student majoring in chemical engineering. Along with interests in the scientific development of nanotechnology and specifically molecular manufacturing (MM), he is very concerned with the socio-political developments that MM will set in motion. We are excited about the energy and creativity that Martin will bring to his activities with CRN. Congratulations, and welcome, Martin!


Events Coordinator

To educate, engage, and empower others to prepare for molecular manufacturing, CRN is now offering two-day Nano-Workshops (see below). There may be a paid position for someone to help us plan and coordinate these events, especially if that person can identify and solicit prospective recipients of workshop presentations. We’re also seeking additional speaking engagements in 2005. Someone who can solicit such opportunities for CRN Principals and manage our speaking and presentation calendar might occupy a part-time paid position, either combined with or separate from managing our workshops. If you’re interested, please contact Executive Director Mike Treder.


Nano-Workshops

One of CRN’s key activities for 2005 will be conducting on-site Nano-Workshops, designed to educate interested groups of people about the impending impacts of molecular manufacturing, to assess how it may affect them and their organizations, and to guide them in deciding what they might do about it. We’ve developed the curriculum, which covers: 1) Technical Background for Molecular Manufacturing; 2) Introduction to Implications; 3) Projections of Molecular Manufacturing Development; and 4) Impact and Implications, with focus on the audience's concerns. The workshops will be interactive, will include group brainstorming, and will aim at forming a long-range action plan for the group to pursue.

Do you know of a company, a school, a nonprofit organization, or another group that might be interested in learning about the future of nanotechnology and how it could affect them? We’re laying out our calendar now, and the first three groups to book a workshop will benefit from a significant discount—so please encourage them to contact us right away.


Symposium on Nanotechnology

In connection with their hugely popular annual conference, the World Future Society has announced "an exploration series designed to provide an outline of several critical new fields with the potential for significant impact on the social, economic, and cultural fabric of modern society." For this year, they have organized a Symposium on Nanotechnology, which Mike Treder will assist in presenting. It’s happening in Chicago on July 29, 2005.


New Paper Posted

The paper that Mike presented at the November 2004 International Congress of Nanotechnology, which is titled "Bridges to Safety, and Bridges to Progress", has been posted on our website.

Here’s the abstract:  Advanced nanotechnology offers unprecedented opportunities for progress—defeating poverty, starvation, and disease, opening up outer space, and expanding human capacities. But it also brings unprecedented risks—massive job displacement causing economic and social disruption, threats to civil liberties from ubiquitous surveillance, and the specter of devastating wars fought with far more powerful weapons of mass destruction. The challenge of achieving the goals and managing the risks of nanotechnology requires more than just brilliant molecular engineering. In addition to scientific and technical ingenuity, other disciplines and talents will be vitally important. No single approach will solve all problems or address all needs. The only answer is a collective answer, and that will demand an unprecedented collaboration—a network of leaders in business, government, academia, and NGOs. It will require participation from people of many nations, cultures, languages, and belief systems. Never before have we faced such a tremendous opportunity—and never before have the risks been so great. We must begin building bridges that will lead to safety and progress for the entire world; bridges that will develop common understanding, create lines of communication, and create a stable structure that will enable humankind to pass safely through the transition into the nano era.


Feature Essay: What Is Molecular Manufacturing?
Chris Phoenix, Director of Research, CRN

The term "molecular manufacturing" has been associated with all sorts of futuristic stuff, from bloodstream robots to grey goo to tabletop factories that can make a new factory in a few hours. This can make it hard for people who want to understand the field to know exactly what's being claimed and studied. This essay explains what the term originally meant, why the approach is thought to be powerful enough to create a field around, why so many futuristic ideas are associated with it, and why some of those ideas are more plausible than they may seem.

Original Definition

Eric Drexler defined the term "molecular manufacturing" in his 1992 technical work Nanosystems. His definition used some other terms that need to be considered first.

Mechanochemistry  In this volume, the chemistry of processes in which mechanical systems operating with atomic-scale precision either guide, drive, or are driven by chemical transformations.

In other words, mechanochemistry is the direct, mechanical control of molecular structure formation and manipulation to form atomically precise products. (It can also mean the use of reactions to directly drive mechanical systems—a process that can be nearly 100% efficient, since the energy is never thermalized.) Mechanochemistry has already been demonstrated: Oyabu has used atomic force microscopes, acting purely mechanically, to remove single silicon atoms from a covalent lattice and put them back in the same spot.

Mechanosynthesis  Chemical synthesis controlled by mechanical systems operating with atomic-scale precision, enabling direct positional selection of reaction sites; synthetic applications of mechanochemistry. Suitable mechanical systems include AFM mechanisms, molecular manipulators, and molecular mill systems.

In other words, mechanosynthesis is the use of mechanically guided molecular reactions to build stuff. This does not require that every reaction be directly controlled. Molecular building blocks might be produced by ordinary chemistry; products might be strengthened after manufacture by crosslinking; molecular manufactured components might be joined into products by self-assembly; and building blocks similar to those used in self-assembly might be guided into chosen locations and away from alternate possibilities. Drexler’s definition continues:

Processes that fall outside the intended scope of this definition include reactions guided by the incorporation of reactive moieties into a shared covalent framework (i.e., conventional intramolecular reactions), or by the binding of reagents to enzymes or enzyme-like catalysts.

The point of this is to exclude chemistry that happens by pure self-assembly and cannot be controlled from outside. As we will see, external control of the reactions is the key to successful molecular manufacturing. It is also the main thing that distinguishes molecular manufacturing from other kinds of nanotechnology.

The principle of mechanosynthesis—direct positional control—can be useful with or without covalent bonding. Building blocks like those used in self-assembly, held together by hydrogen bonding or other non-covalent interactions, could also be joined under mechanical control. This would give direct control of the patterns formed by assembly, rather than requiring that the building blocks themselves encode the final structure and implement the assembly process.

Molecular manufacturing  The production of complex structures via nonbiological mechanosynthesis (and subsequent assembly operations).

There is some wiggle room here, because "complex structures" is not defined. Joining two molecules to make one probably doesn't count. But joining selected monomers to make a polymer chain that folds into a predetermined shape probably does.

Machine-phase chemistry  The chemistry of systems in which all potentially reactive moieties follow controlled trajectories (e.g., guided by molecular machines working in vacuum).

This definition reinforces the point that machine-phase chemistry is a narrow subset of mechanochemistry. Mechanochemistry does not require that all molecules be controlled; it only requires that reactions between the molecules must be controlled. Mechanochemistry is quite compatible with "wet" chemistry, as long as the reactants are chosen so that they will only react in the desired locations. A ribosome appears to fit the requirement; Drexler specified that molecular manufacturing be done by nonbiological mechanosynthesis, because otherwise biology would be covered by the definition.

Although it has not been well explored, machine-phase chemistry has some theoretical advantages that make it worth further study. But molecular manufacturing does not depend on a workable machine-phase chemistry being developed. Controversies about whether diamond can be built in vacuum do not need to be settled in order to assess the usefulness of molecular manufacturing.

Extending Molecular Manufacturing

As explained in the first section, the core of molecular manufacturing is the mechanical control of reactions so as to build complex structures. This simple idea opens up a lot of possibilities at the nanoscale. Perhaps the three most important capabilities are engineering, blueprint delivery, and the creation of manufacturing tools. These capabilities reinforce each other, each facilitating the others.

It is often thought that the nanoscale is intractably complex, impossible to analyze. Nearly intractable complexity certainly can be found at the nanoscale, for example in the prediction of protein folding. But not everything at the nanoscale is complex. DNA folding, for example, is much simpler, and the engineering of folded structures is now pretty straightforward. Crystals and self-assembled monolayers also have simple aspects: they are more or less identical at a wide range of positions. The mechanical properties of nanoscale structures change as they get extremely small, but even single-nanometer covalent solids (diamond, alumina, etc) can be said to have a well-defined shape.

The ability to carry out predictable synthesis reactions at chosen sites or in chosen sequences should allow the construction of structures that are intricate and functional, but not intractably complex. This kind of approach is a good fit for engineering. If a structure is the wrong shape or stiffness, simply changing the sequence of reactions used to build it will change its structure—and at least some of its properties—in a predictable way.

It is not always easy to control things at the nanoscale. Most of our tools are orders of magnitude larger, and more or less clumsy; it's like trying to handle toothpicks with telephone poles. Despite this, a few techniques and approaches have been developed that can handle individual molecules and atoms, and move larger objects by fractions of nanometers. A separate approach is to handle huge numbers of molecules at once, and set up the conditions just right so that they all do the same thing, something predictable and useful. Chemistry is an example of this; the formation of self-assembled monolayers is another example. The trouble with all of these approaches is that they are limited in the amount of information that can be delivered to the nanoscale. After a technique is used to produce an intermediate product, a new technique must be applied to perform the next step. Each of these steps is hard to develop. They also tend to be slow to use, for two reasons: big tools move slowly, and switching between techniques and tools can take a lot of time.

Molecular manufacturing has a big advantage over other nanoscale construction techniques: it can usefully apply the same step over and over again. This is because each step takes place at a selected location and with selected building blocks. Moving to a different location, or selecting a different building block from a predefined set, need not insert enough variation into the process to count as a new step that must be developed and characterized separately.

A set of molecular manufacturing operations, once worked out, could be recombined like letters of an alphabet to make a wide variety of predictable products. (This benefit is enhanced because mechanically guided chemistry can play useful games with reaction barriers to speed up reactions by many orders of magnitude; this allows a wider range of reactants to be used, and can reduce the probability of unwanted side reactions.) The use of computer-controlled tools and computer-aided translation from structure to operation sequence should allow blueprints to be delivered directly to the nanoscale.

Although it is not part of the original definition of molecular manufacturing, the ability to build a class of product structures that includes manufacturing the tools used to build them may be very useful. If the tools can be engineered by the same skill set that produces useful products, then research and development may be accelerated. If new versions of tools can be constructed and put into service within the nanoscale workspace, that may be more efficient than building new macro-scale tools each time a new design is to be tested. Finally, if a set of tools can be used to build a second equivalent set of tools, then scaleup becomes possible.

The idea of a tool that can build an improved copy of itself may seem counterintuitive: how can something build something else that's more complex than itself? But the inputs to the process include not just the structure of the first tool, but the information used to control it. Because of the sequential, repetitive nature of molecular manufacturing, the amount of information that can be fed to the process is essentially unlimited. A tool of finite complexity, controlled from the outside, can build things far more physically complex than itself; the complexity is limited by the quality of the design. If engineering can be applied, then the design can be quite complex indeed; computer chips are being designed with a billion transistors.

From the mechanical engineering side, the idea of tools building tools may be suspect because it seems like precision will be lost at each step. However, the use of covalent chemistry restores precision. Covalent reactions are inherently digital: in general, either a bond is formed which holds the atoms together, or the bond is missing and the atoms repel each other. This means that as long as the molecules can be manipulated with enough precision to form bonds in the desired places, the product will be exactly as it was designed, with no loss of precision whatsoever. The precision required to form bonds reliably is a significant engineering requirement that will require careful design of tools, but is far from being a showstopper.

Scaleup

The main limitation of molecular manufacturing is that molecules are so small. Controlling one reaction at a time with a single tool will produce astonishingly small masses of product. At first sight, it may appear that there is no way to build anything useful with this approach. However, there is a way around this problem, and it’s the same way used by ribosomes to build an elephant: use a lot of them in parallel. Of course, this requires that the tools must be very small, and it must be possible to build a lot of them and then control them all. Engineering, direct blueprint injection, and the use of molecular manufacturing tools to build more tools can be combined to achieve this.

The key question is: How rapidly can a molecular manufacturing tool create its own mass of product? This value, which I'll call "relative productivity," depends on the mass of the tool; roughly speaking, its mass will be about the cube of its size. For each factor of ten shrinkage, the mass of the tool will decrease by 1,000. In addition, small things move faster than large things, and the relationship is roughly linear. This means that each factor of ten shrinkage of the tool will increase its relative productivity by 10,000 times; relative productivity increases as the inverse fourth power of the size.

A typical scanning probe microscope might weigh two kilograms, have a size of about 10 cm, and carry out ten automated operations per second. If each operation deposits one carbon atom, which masses about 2x10-26 kg, then it would take 1026 seconds or six billion billion years for that scanning probe microscope to fabricate its own mass. But if the tool could be shrunk by a factor of a million, to 100 nm, then its relative throughput would increase by 1024, and it would take only 100 seconds to fabricate its own mass. This assumes an operation speed of 10 million per second, which is about ten times faster than the fastest known enzymes (carbonic anhydrase and superoxide dismutase). But a relative productivity of 1,000 or even 10,000 seconds would be sufficient for a very worthwhile manufacturing technology. (An inkjet printer takes about 10,000 seconds to print its weight in ink.) Also, there is no requirement that a fabrication operation deposit only one atom at a time; a variety of molecular fragments may be suitable.

To produce a gram of product will take on the order of a gram of nanoscale tools. This means that huge numbers of the tools must be controlled in parallel: information and power must be fed to each one. There are several possible ways to do this, including light and pressure. If the tools can be fastened to a framework, it may be easier to control them, especially if they can build the framework and include nanoscale structures in it. This is the basic concept of a nanofactory.

Nanofactories and Their Products

A nanofactory is (will be) an integrated manufacturing system containing large numbers of nanoscale molecular manufacturing workstations (tool systems). This appears to be the most efficient and engineerable way to make nanoscale productive systems produce large products. With the workstations fastened down in known positions, their nanoscale products can more easily be joined. Also, power and control signals can be delivered through hardwired connections.

The only way to build a nanofactory is with another nanofactory. However, the product of a nanofactory may be larger than itself; it does not appear conceptually or practically difficult to build a small nanofactory with a single molecular manufacturing tool, and build from there to a kilogram-scale nanofactory. The architecture of a nanofactory must take several problems into account, in addition to the design of the individual fabrication workstations. The mass and organization of the mounting structure must be included in the construction plans. A small fraction (but large number) of the nanoscale equipment in the nanofactory will be damaged by background radiation, and the control algorithms will have to compensate for this in making functional products. To make heterogeneous products, the workstations and/or the nanoproduct assembly apparatus must be individually controlled; this probably requires control logic to be integrated into the nanofactory.

It may seem premature to be thinking about nanofactory design before the first nanoscale molecular manufacturing system has been built. But it is important to know what will be possible, and how difficult it will be, in order to estimate the ultimate payoff of a technology and the time and effort required to achieve it. If nanofactories were impossible, then molecular manufacturing would be significantly less useful; it would be very difficult to make large products. But preliminary studies seem to show that nanofactories are actually not very difficult to design, at least in broad outline. I have written an 80-page paper that covers error handling, mass and layout, transport of feedstock, control of fabricators, and assembly and design of products for a very primitive nanofactory design. My best estimate is that this design could produce a duplicate nanofactory in less than a day. Nanofactory designs have been proposed that appear to be much more flexible in how the products are formed, but they have not yet been worked out in as much detail.

If there is a straightforward path from molecular manufacturing to nanofactories, then useful products will not be far behind. The ability to specify every cubic nanometer of an integrated kilogram product, filling the product with engineered machinery, will at least allow the construction of extremely powerful computers. If the construction material is strong, then mechanical performance may also be extremely good; scaling laws predict that power density increases as the inverse of machine size, and nanostructured materials may be able to take advantage of almost the full theoretical strength of covalent bonds rather than being limited by propagating defects.

Many products have been imagined for this technology. A few have been designed in sufficient detail that they might work as claimed. Robert Freitas's Nanomedicine Vol. I contains analyses of many kinds of nanoscale machinery. However, this only scratches the surface. In the absence of more detailed analysis identifying quantitative limits, there has been a tendency for futurists to assume that nano-built products will achieve performance close to the limits of physical law. Motors three to six orders of magnitude more powerful than today's; computers six to nine orders of magnitude more compact and efficient; materials at least two orders of magnitude stronger—all built by manufacturing systems many orders of magnitude cheaper—it's not hard to see why futurists would fall in love with this field, and skeptics would dismiss it. The solution is threefold: 1) open-minded but quantitative investigation of the theories and proposals that have already been made; 2) constructive attempts to fill in missing details; and 3) critical efforts to identify unidentified problems with the application of the theories.

Based on a decade and a half of study, I am satisfied that some kind of nanofactory can be made to work efficiently enough to be more than competitive with today's manufacturing systems, at least for some products. In addition, I am satisfied that molecular manufacturing can be used to build simple, high-performance nanoscale devices that can be combined into useful, gram-scale, high-performance products via straightforward engineering design. This is enough to make molecular manufacturing seem very interesting, well worth further study; and in the absence of evidence to the contrary, worth a measure of preliminary concern over how some of its possible products might be used.

C-R-Newsletter #26    January 3, 2005

CONTENTS

Happy Birthday to CRN!
X Prize Proposals
CRN Blog Highlights
Nano-Workshops
Staff Positions Available
Year in Review
Feature Essay: Advantages of Engineered Nanosystems

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Happy Birthday to CRN!

In December 2002, Chris Phoenix and Mike Treder founded the Center for Responsible Nanotechnology. So, we've just celebrated our second birthday. It's been an eventful two years, with a lot learned and, we think, a lot accomplished. Many thanks to all of you who have contributed your time, your advice, your financial support, and your interest in our work. We're looking forward to another great year in 2005.


X Prize Proposals

The X Prize people—who inspired SpaceShipOne—are at it again, and this time they're interested in molecular manufacturing (among other things). CRN is suggesting a prize proposal to encourage the development of a primitive molecular manufacturing capability. We believe this is the responsible thing to do. The machine we describe would make less powerful products, which we think implies less disruption. What it would do is serve as a proof of principle and stimulate discussion.

Chris has created a Wise-Nano page containing his proposal. The page also contains another X-prize proposal by Robert Freitas (author of Nanomedicine) that's intended to jump-start diamondoid molecular manufacturing more directly. Although the proposals have been submitted already, comments are welcomed at the Wise-Nano "discussion" page.


CRN Blog Highlights

A few of the more interesting subject headings of the last month at our blog site, which have inspired fascinating discussions, are:

bullet Wisdom Isn’t Easy
bullet Upside vs. Downside
bullet Invisibility
bullet Transformative Impacts

The daily weblog continues to be both a rewarding and an increasingly popular project for CRN.


Nano-Workshops

One of CRN's key activities for 2005 will be conducting on-site Nano-Workshops, designed to educate interested groups of people about the impending impacts of molecular manufacturing, to assess how it may affect them and their organizations, and to guide them in deciding what they might do about it. We've developed the curriculum, which covers: 1) Technical Background, 2) Implications Foundation, 3) Development, and 4) Targeted Impact. The workshops will be interactive, will include group brainstorming, and will aim at forming a long-range action plan for the group to pursue.

Do you know of a company, a school, a nonprofit organization, or another group that might be interested in learning about the future of nanotechnology and how it could affect them? We're laying out our calendar now, and the first three groups to book a workshop will benefit from a significant discount—so please encourage them to contact us right away.


Staff Positions Available

For CRN to become an even stronger worldwide influence in the development of responsible nanotechnology policy, we must expand in 2005. We need assistance from volunteer workers and possibly also from paid staff (part-time to start). The jobs we need to fill are in three general areas: Organization, Communications, and Appearances.

Organization – We need someone to help maintain records of C-R-Network membership, coordinate communication with Network members, promote opportunities for student research collaborations within educational networks, and so on. This is a volunteer job, which might require 10 to 20 hours per month.

Communications – There are several functions that fall under this heading, such as writing/editing this newsletter, maintaining an up-to-date newsletter subscription list, and compiling and publishing our quarterly Responsible Nanotechnology Report. Other jobs, which could be handled by one or more volunteers, include editing and monitoring CRN's daily weblog, editing the Wise-Nano.org site, and coordinating the publication of our CRN Nano-Workbooks.

Appearances – To educate, engage, and empower others to prepare for molecular manufacturing, CRN is now offering two-day Nano-Workshops (see above). There may be a paid position for someone to help us plan and coordinate these events, especially if that person can identify and solicit prospective recipients of workshop presentations. We're also seeking additional speaking engagements in 2005. Someone who can solicit such opportunities for CRN Principals and manage our speaking and presentation calendar might occupy a part-time paid position, either combined with or separate from managing our workshops.

If you want more information about filling any of these roles, please contact Executive Director Mike Treder. Thanks!


Year in Review

All in all, 2004 was a remarkable 12 months for CRN, and for nanotechnology in general. Let's see, we traveled to China, Brazil, England, Canada, and all around the USA to give speeches and presentations. We made highly valuable contacts in Sweden, India, Spain, Turkey, Italy, and many other places. Chris was awarded a research grant from NASA's Institute for Advanced Concepts, and Mike was able to start working full-time for CRN. We opened beneficial dialogue with government officials in the United States and other countries. Perhaps most rewarding is the contribution we made in elevating the level of discussion about responsible development of nanotechnology, and our success in engaging skeptics and critics in productive debate. Whew, what a year!

We're preparing a more detailed rundown of our activities in 2004 for publication in our next Quarterly Report. You'll receive that if you are a member of the C-R-Network, and if you're not, perhaps you should sign up.


Feature Essay: Advantages of Engineered Nanosystems
Chris Phoenix, Director of Research, CRN

Today, biology implements by far the most advanced nanomachines on the planet. It is tempting to think that biology must be efficient, and that we can't hope to design nanomachines with higher performance. But we already know some techniques that biology has never been able to try. This essay discusses several of them and explains why biology could not use them, but manufactured nanomachines will be able to.

Low Friction Via Superlubricity

Imagine you're pulling a toy wagon with square wheels. Each time a wheel turns past a corner, the wagon lurches forward with a thump. This would waste substantial amounts of energy. It's as though you're continually pulling the wagon up tiny hills, which it then falls off of. There's no way to avoid the waste of energy.

At the molecular scale, static friction is like that. Forces between the molecules cause them to stretch out of position, then snap into a new configuration. The snap, or clunk, requires energy—which is immediately dissipated as heat.

In order for a sliding interface to have low friction, there must be an extremely small difference in energy between all adjacent positions or configurations. But between most surfaces, that is not the case. The molecular fragments at the surface are springy and adhesive enough that they grab hold, get pulled, and then snap back, wasting energy.

There are several ways in which a molecule can be pulled or pushed out of position. If the interface is rough or dirty, the surfaces can be torn apart as they move. This of course takes a lot of energy, producing very high friction. Even apparently smooth surfaces can be sources of friction. If the surface is coated with molecular bumps, the bumps may push each other sideways as they go past, and then spring back, wasting energy. Even if the bumps are too short and stiff to be pushed sideways very far, they can still interlock, like stacking egg cartons or ice cube trays. (Thanks to Wikipedia for this analogy.) If the bumps interlock strongly, then it may take a lot of force to move them past each other—and just as they pass the halfway point, they will snap into the next interlocking position, again wasting energy.

One way to reduce this kind of friction is to separate the surfaces. A film of water or oil can make surfaces quite slippery. But another way to reduce friction is to use stiff surfaces that don't line up with each other. Think back to the egg-carton image. If you turn one of the cartons so that the bumps don't line up, then they can't interlock; they will simply skim past each other. In fact, friction too low to measure has been observed with graphite sheets that were turned so as to be out of alignment. Another way to prevent alignment is to make the bumps have different spacing, by choosing different materials with different atoms on their surfaces.

This low-friction trick, called superlubricity, is difficult to achieve in practice. Remember that the surfaces must be very smooth, so they can slip past each other; and very stiff, so the bumps don't push each other sideways and spring back; and the bumps must not line up, or they will interlock. Biological molecules are not stiff enough to use the superlubricity trick. Superlubricity may be counterintuitive to people who are accustomed to the high friction of most hard dry surfaces. But experiments have shown [PDF] that superlubricity works. A variety of materials that have been proposed for molecular manufacturing should be stiff enough to take advantage of superlubricity.

Electric Currents

The kind of electricity that we channel in wires is made up of vast quantities of electrons moving through the wire. Electrons can be made to move by a magnetic field, as in a generator, or by a chemical reaction, as in a battery. Either way, the moving electrons can be sent for long distances, and can do useful work along the way. Electricity is extremely convenient and powerful, a foundation of modern technology.

With only a few exceptions like electric eels, biological organisms do not use this kind of electricity. You may know that our nerve cells use electricity. But instead of moving electrons, biology uses ions—the "charged" atoms that remain when one or more electrons are removed. Ions can move from place to place, and can do work just like electrons. Bacteria use ions to power their flagella "tails." Ions moving suddenly through a nerve cell membrane cause a change that allows more ions, further along the cell, to be able to move, creating a domino effect that ripples from one end of the cell to the other.

Ions are convenient for cells to handle. An ion is much larger than an electron, and is therefore easier to contain. But ions have to move slowly, bumping through the water they are dissolved in. Over long distances, electrons in a wire can deliver energy far more rapidly than ions in a liquid. But wires require insulation.

It is perhaps not surprising that biology hasn't used electron currents. At cellular scales, ions diffuse fast enough to do the job. And the same membranes that keep chemicals properly in (or out of) the cell can also keep ions contained where they can do useful work. But if we actually had "nerves of steel", we could react far more quickly than we do.

To use electron currents, all that's needed is a good conductor and a good insulator. Carbon nanotubes can be both conductors and insulators, depending on how they are constructed. Many organic molecules are insulating, and some are conductive. There is a lot of potential for molecular manufacturing to build useful circuits, both for signaling and for power transmission.

Deterministic Machines

Cells have to reconfigure themselves constantly in response to changing conditions. They are built out of individual molecules, loosely associated. And the only connection between many of the molecular systems is other molecules diffusing randomly through the cell's interior. This means that the processes of the cell will happen unpredictably, from molecules bumping into each other after a random length of time. Such processes are not deterministic: there's no way to know exactly when a reaction or process will happen. This lack of tight connection between events makes the cell's processes more adaptable to change, but more difficult to engineer.

Engineered nanosystems can be designed, and then built and used, without needing to be reconfigured. That makes it easier to specify mechanical or signal linkages to connect them and make them work in step, while a constantly changing configuration would be difficult to accommodate. Of course, no linkage is absolutely precise, but it will be possible to ensure that, for example, an intermediate stage in a manufacturing process always has its input ready at the time it begins a cycle. This will make design quite a bit easier, since complex feedback loops will not be required to keep everything running at the right relative speed. This also makes it possible to use standard digital logic circuits.

Digital Logic

Digital logic is general-purpose and easy to engineer, which makes it great for controlling almost any process. But it requires symbolic codes and rapid, reliable computation. There is no way that the diffuse statistical chemical signaling of biology could implement a high-speed microprocessor (CPU). But rapid, lock-stepped signals make it easy. Biology, of course, doesn't need digital logic, because it has complex control loops. But complex things are very difficult to engineer. Using digital logic instead of complexity will allow products to be designed much more quickly.

Rapid Transport and Motion

Everything in a cell is flooded with water. This means that everything that moves experiences high drag. If a nanomachine can be run dry, its parts can move more efficiently and/or at higher speeds.

Things that move by diffusion are not exempt from drag: it takes as much energy to make objects diffuse from point A to point B in a certain time as it does to drag it there. Although diffusion seems to happen "by itself", to work as a transportation system it requires maintaining a higher concentration of particles (e.g. molecules) at the source than at the destination. This requires an input of work.

In a machine without solvent, diffusion can't work, so particles would have to be transported mechanically. (In theory, certain small molecules could be released into vacuum and bounce around to their destination, but this has practical difficulties that probably would make it not useful.) Mechanical transportation sounds inefficient, but in fact it can be more efficient than diffusion. Because the particle is never released, energy is not required to find and recapture it. Because nothing has to move through fluid, frictional forces can be lower for the same speed, or speeds can be higher for the same energy consumption. The use of machinery to move nanoparticles and molecules may seem wasteful, but it replaces the need to maintain a pathway of solvent molecules; it may actually require less mass and volume. The increased design complexity of the transport machinery will be more or less balanced by the reduced design complexity of the receiving stations for particles.

It is not only transport that can benefit from running without solvent. Any motion will be subject to drag, which will be much higher in liquid than in gas or vacuum. For slow motions, this is not so important. But to obtain high power density and processing throughput, machines will have to move quickly. Drying out the machines will allow greater efficiency than biology can attain. Biology has never developed the ability to work without water. Engineered machines can do so.

 

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