Nanoparticles, Nanodevices, Nanofactories

An article by Jamais Cascio makes a good start at describing three levels of nanotechnology: nanoparticles, nanomachines, and nanofactories. Astute readers will note that the title of this blog entry replaces "nanomachines" with "nanodevices." I'll explain why later on.

There are a lot of "nano" concepts to be sorted out. They have to be plotted in two dimensions, ranging from primitive to advanced, and from mundane through fantastic to impossible. Jamais's article, though quite useful, does not draw enough distinctions to clear up all the confusions.

By "mundane," I mean things that are completely consistent with physics and engineering as they are understood today; things that may require a lot of work to develop, but don't require new scientific breakthroughs; things that we could start designing and developing, and in some cases already have.

A primitive example of a mundane nanotechnology is nanoparticles. A more advanced example is nanodevices that are starting to be developed today: active things like transistors and molecular actuators. Nanomanufacturing is a term for early attempts to take a more active role in building more intricate nanostructures -- though not necessarily using molecular bonds or molecular precision. This is gradually being developed in order to build better nanodevices, reflecting the realization that it's not enough to make small stuff -- to be really useful, the stuff has to be intricate (information-rich), and this requires more than bulk processes (including pure self-assembly).

Perhaps the most advanced mundane nanotechnology that has been proposed is the nanofactory outlined in 1992 by Eric Drexler (Chapter 14 of Nanosystems) and fleshed out over the last few years by Burch and Drexler, and by CRN projects. Calculating the capabilities of nanofactories is the best way I know to understand what molecular manufacturing will be capable of -- at least at first.

A lot of less mundane (fantastic) nanotechnologies have been proposed: things that would be very powerful or useful, that are probably doable, but that we don't know enough to really start designing yet. A lot of nanomedical devices fall into this category. We can speculate about them, sometimes in more or less detail, but we can't really finish the design until we learn more about how the body works. Some of the more advanced aerospace proposals fall into this category.

Nanobots fall somewhere between fantastic and impossible. Science fiction hardly ever manages to get it right; even when the authors try to be physically plausible, they usually mess up some constraint like heat or raw materials or operation speed.

Before Drexler developed the nanofactory concept, he had an earlier idea of small cooperating fabrication robots, which he called "assemblers." The operation of assemblers was never described in detail, and making them work together would require major advances if not breakthroughs in robotics. In short, I would have to classify them as non-mundane -- fantastic -- though probably not impossible. Unfortunately, the assemblers became almost immediately mythologized as "universal" nanobots that could do nearly-impossible tasks like efficiently pulling apart unsorted raw materials to rearrange the atoms into new products.

This is why I suggest that "nanodevices" is a better word than "nanomachines" to describe the evolution of practical nanotechnology. To me, "nanomachine" sounds potentially a lot more complicated and functional than "nanodevice." This is reflected in Jamais's article, where he describes two things that he classifies as nanomachines. One is a simple molecular actuator that's being developed today. The other is Drexler's superseded semi-fantastic assembler concept. It's better to use a word like "nanodevice" that helps to make it clear that the simple devices being developed today have no relation to assemblers or other nanobots.

In just a few years, with only the general guiding principle that small novel stuff is likely to be worth studying, the National Nanotechnology Initiative has moved from nanoparticles to nanodevices and nanomanufacturing. (By the way, I don't like the term "nanomanufacturing" because it is confusing: it sounds like it includes nanofactory-level technology, although it is actually a far more modest and special-purpose set of technologies. But the NNI has adopted it, so we're stuck with it.)

The natural course of nanotech development is to fasten together smaller particles, with more precision, with stronger bonds, with more programmability, to make more intricate devices. In perhaps 20 years, work funded by the NNI could lead to nanofactory-level technologies without much planning or direction. However, it's worth talking about nanofactories and their consequences today, for two reasons. First, they will be easier to develop than most nanotechnologists realize -- and because a few do realize it, nanofactories might be developed early and take a lot of people even in the nanotech community by surprise. Second, they are an extremely powerful tool for nanoscale R&D, and at the same time an extremely powerful tool for making advanced products.

As nanotech develops, it will become clearer that there is a continuum from nanoparticles, through nanodevices, to nanofactories. There are times when it's important to make the distinction clear: molecular manufacturing is fundamentally different from nanoscale technologies in many ways, both in approach and implications. But it is becoming increasingly possible and useful to chart the evolution of goals and the development pathways.

Chris Phoenix

Tags: nanotechnology nanotech nano science technology ethics weblog blog

Comments

[Jamais Cascio]

Thanks, Chris. This is a useful clarification and update. The divide between mundane and fantastic makes sense, although I'm curious about the inclusion of nanomedical technologies in the "fantastic" category. There are already some fairly primitive medical uses of nanoscale technologies, usually with a macroscale interaction (I'm thinking of the IR-illuminated nanoparticles as a method of killing cancer cells). There's also some research use of carbon nanotubes as the base material for tissue scaffolding. Nothing at all like the cholesterol-zapping nanobots of our Dorito-laden dreams, but certainly just as nanotech as (say) nanopants.

[Tom Craver]

Since the NNI has pretty much taken control of the term "nano", and continues to usurp new terms like "nanomanufacturing", how about switching to "mole" for terminology?

"moletech" - catchier than molecular nanotech or MNT.
"molefactory" - an MNT factory
"molefacture" - to build in a molefactory
"molepart" - a molecular-scale component
"moletecture" - a design using moleparts
"moleactive" - having powered moleparts

[Pace Arko]

Sigh. I've been reading news about the marketroids, research grants and government functionaries usurping the terminology for four or so years now and I don't know if coming up with new terms at this will really help.

I'm sure that software engineers are still irritated with harddrive specs in ads magazines that don't distinguish between binary megabytes (MiBs) which accurately count storage space and decimal "MegaBytes" (MB) which don't.

So it goes.

[Chris Phoenix, CRN]

Jamais, I didn't say or intend that all medical nanotech was fantastic. And I wasn't thinking at all about nanoscale technologies. I was thinking about things closer to the "bloodstream nanobot" end of the spectrum.

Among molecular-manufactured medical devices that have been proposed, about the only semi-non-fantastic one I can think of is Freitas's respirocytes; they may have simple enough functionality that we could engineer them with what we know today. Some of Freitas's other proposed devices may be non-fantastic, but I haven't studied in enough detail to say for sure.

Tom, Drexler tried "zetta" as a prefix a year or two ago, and it didn't get anywhere. "Mole" seems a bit better, because it sounds like both Avogadro's number and molecular.

Note that CRN chose to use "molecular manufaturing" rather than "molecular nanotechnology" to describe the field. "Molefacturing" seems better than "nano-manufacturing" (which is ambiguous). But "moleblock" and "molefactory" don't have the ring for me that "nanoblock" and "nanofactory" do.

Start using it and see if it catches on.

Chris

[Matt]

" 'Mole' seems a bit better, because it sounds like both Avogadro's number and molecular."

It also sounds like a small furry mammal that blights home owners' gardens with heaps of excavated earth; you might want to avoid this connotation. Maybe it's just me, but I found Tom's post rather humorous, if not subtly satirical :)

Joking aside, I believe the "nano"-prefix is pretty much lost for MNT and will only return to its origins (Engines of Creation) when scientific theory, scientific experiment, and engineering agree beyond reasonable doubt that MNT in form of a nanofactory is possible. I would consider "engineering agrees" as "there is a functional prototype of a nanomanipulator that does basic mechanochemistry and we have the ability to integrate billions of them into a working factory". This might also mean that preparing for nanotechnology as CRN understands it is only possible when that agreement has been achieved, because until then, CRN's "nanotechnology" and the public's "nanotechnology" will mostly represent two different things.

Until this return of "nano" to its origins, however, CRN should stay true to nano's history, because when the time comes, you will not have to change the prefix AGAIN to fit the new old fashion.

[Phillip Huggan]

I like Molecular Manufacturing because MM is versatile. The subject can be MMed, a MMer, or just plain MM to suggest Molecular Manufacture. The suffixes can even be dropped without the idea conveyed being lost. MNTing and MNTed pronounced "minted" and "minting" to imply nanofactories or nanoproducts, still has appeal to me too.

[Dave]

"...they will be easier to develop than most nanotechnologists realize -- and because a few do realize it, nanofactories might be developed early and take a lot of people even in the nanotech community by surprise."

Why do few nanotechnologists realise how easy nanofactories will be to develop? I've heard this claim many times but never really heard any explanation of exactly why. Is it because each is concentrating on their own little piece, and so is blinded to the broader picture?

[Chris Phoenix, CRN]

Most nanotechnologists are working with complex analog phenomena at the limits of theory. Nanofactories will depend on straightforward digital phenomena using mostly decades-old theory.

Many nanotechnologists have heard the party line that "nanobots are impossible" and "ignore Drexler." Some have never looked for themselves.

Living organisms are insanely complex. Some nanotechnologists, especially those who study biology, have the idea that this complexity is 1) good and 2) necessary for any large nano-based device. Ain't so, any more than a billion-transistor computer chip has to be complex. (It's very intricate, but not complex.)

It takes a modern PC about a week to do a mole of transistor operations. It will do them all flawlessly, in a very intricate pattern. If we can design this, we can design a nanofactory.

In fact, the nanofactory will be easier in some ways, because it doesn't need as much software. (The accompanying CAD program could have lots and lots of software, but even a relatively simple program would be able to specify simple products. A nanofactory will be a comparatively simple product.)

Chris

[Matt]

Also look here:

http://www.niac.usra.edu/studies/study.jsp?id=883&cpnum=02-02&phase=I&last=Toth-Fejel&first=Tihamer&middle=&title=Modeling%20Kinematic%20Cellular%20Automata:%20An%20Approach%20to%20Self-Replication&organization=Veridian%20Systems%20Division,%20Inc.&begin_date=2003-10-01%2000:00:00.0&end_date=2004-03-31%2000:00:00.0> (pleeease give back html, or make auto-parsing optional).
This study says a nanofactory would be as complex as a Pentium 4 microprocessor.

http://www.wired.com/wired/archive/13.09/fablab.html
Here you find a nice Wired article about eMachineShop, a personal manufacturing service.

[Philip Moriarty]

Dave asks "Why do few nanotechnologists realise how easy nanofactories will be to develop?" as if there's already a viable pathway to nanofactory development. He also asks whether the general scepticism re. nanofactories is a question of nanotechnologists being "blinded to the bigger picture"! Is it not just a little patronising to assume that those who don't embrace MNT are somehow lacking in vision? You may like to visit http://www.softmachines.org/wordpress/?p=130 for an alternative viewpoint!

Chris replies: "Many nanotechnologists have heard the party line that "nanobots are impossible" and "ignore Drexler." Some have never looked for themselves."

...and some have. Please feel free, if you wish, to continue to ignore the input/efforts of those in the scientific community who have spent the time to critique MNT concepts. I note from previous posts on the CRN blog that scepticism is apparently seen as unwelcome and something to avoid. In any scientific venture, a healthy dose of scepticism is generally extremely useful. It is only by addressing your critics' lack of faith in nanofactory development that you'll streamline your ideas and perhaps approach a *material-specific* concept rather than put forward broad generalisations as is currently the case. If the criticism and advice of MNT sceptics were taken on board (rather than being ignored) there may well be benefits for both the MNT and - for want of a better term - 'conventional' nanotech communities. For example, the development of scanning probe atomic/molecular manipulation strategies for MNT (a la Freitas, Merkle et al.) is producing theoretical data that are of value for both the MNT and conventional nanotech communities.

Best wishes,

Philip

PS I agree with Matt - please put HTML parsing back. (It took me long enough to find out that I could use it in the first place...!)