What kind of nanomachines will advanced nanotechnology use?

Dr. Richard Jones
Dr. Richard Jones

Long-term readers of Nanodot will be familiar with the work of Richard Jones, a UK physicist and author of Soft Machines: Nanotechnology and Life, reviewed in Foresight Update Number 55 (2005) page 10. Basically Jones follows Eric Drexler’s lead in Engines of Creation in arguing that the molecular machinery found in nature provides an existence proof of an advanced nanotechnology of enormous capabilities. However, he cites the very different physics governing biomolecular machinery operating in an aqueous environment on the one hand, and macroscopic machine tools of steel and other hard metals, on the other hand. He then argues that rigid diamondoid structures doing atomically precise mechanochemistry, as later presented by Drexler in Nanosystems, although at least theoretically feasible, do not form a practical path to advanced nanotechnology. This stance occasioned several very useful and informative debates on the relative strengths and weaknesses of different approaches to advanced nanotechnology, both on his Soft Machines blog and here on Nanodot (for example “Debate with ‘Soft Machines’ continues“, “Which way(s) to advanced nanotechnology?“, “Recent commentary“). An illuminating interview of Richard Jones over at h+ Magazine not only presents Jones’s current views, but spotlights the lack of substantial effort since 2008 in trying to resolve these issues “Going Soft on Nanotech“:

… RJ: I’m both a fan of Eric Drexler and a critic — though perhaps it would be most correct to say I’m a critic of many of his fans. Like many people, I was inspired by the vision of Engines of Creation, in outlining what would be possible if we could make functional machines and devices at the nanoscale. If Engines set out the vision in general terms, Nanosystems was a very thorough attempt to lay out one possible concrete realisation of that vision. Looking back at it twenty years on, two things strike me about it. One was already pointed out by Drexler himself — it says virtually nothing about electrons and photons, so the huge potential that nanostructures have to control their interaction, which forms the basis of the actually existing nanotechnologies that underlie electronic and optoelectronic devices, is unexplored. The other has only become obvious since the writing of the book. Engines of Creation draws a lot on the example of cell biology as an existence proof that advanced nanoscale machines, operating with atom precision, can be made. This represents one of Drexler’s most original contributions to the formation of the idea of nanotechnology — Feynman’s famous 1959 lecture, in contrast, had very little to say about biology. Since Nanosystems was written, though, we’ve discovered a huge amount about the mechanisms of how the nanomachines of biology actually work, and even more importantly, why they work in the way they do; what this tells us is that biology doesn’t use the paradigm of scaling down macroscopic mechanical engineering that underlies Nanosystems. So while it’s right to say that biology gives us an existence proof for advanced nanotechnology, it doesn’t at all support the idea that the mechanical engineering paradigm is the best way to achieve it. The view I’ve come to is that, on the contrary, the project of scaling down mechanical engineering to atomic dimensions will be very much more difficult than many of Drexler’s followers think. …

H+: In 2005, you proposed six important things MNT [an acronym for “molecular nanotechnology”, otherwise termed “molecular manufacturing” or “atomically precise manufacturing”] proponents could do to bolster the feasibility of MNT. They are listed below. How much progress have they made meeting your challenge?

  • Do more detailed and realistic computer modeling of hypothesized nanomachine components (gears, shafts, etc.) to determine if they would hold their shapes and not disintegrate or bend if actually built.
  • Re-do computer simulations of MNT nanomachines, this time using realistic assumptions about Brownian motion and thermal noise. The nanomachines’ “hard” parts would be more like rubber, and they would experience intense turbulence at all times. Delicate nanomachine mechanisms could be easily destroyed.
  • Re-do nanomachine computer simulations to realistically account for friction between the moving parts and for heat buildup. Heat and vibration could destroy nanomachines.
  • Do more detailed computer simulations of Drexler’s nano-scale motor to make sure it would actually work. He never modeled it down to the level of individual atoms. The motor is a critical component in Drexler’s theoretical nanomachine designs as it powers many of the moving parts.
  • Design a nano-scale valve or pump that selectively moves matter between the nanomachine’s enclosed inner area and the ambient environment. To be useful, nanomachines would need to “ingest” matter, modify it internally, and then expel it, but they would also have to block entry of unwanted matter that would jam up their exposed nano-moving parts. A valve or pump that is 100% accurate at discriminating between good and bad foreign materials is thus needed.
  • Flesh out a convincing, multi-year implementation plan for building the first MNT nanomachines. Either top-down or bottom-up approaches may be pursued. In either case, the plan must be technically feasible and must make sense.

[Source: http://www.softmachines.org/wordpress/?p=175]

RJ: Not a great deal, as far as I can tell. There was some progress made on points 1, 2 and 3 following the introduction of the software tool Nanoengineer by the company Nanorex, but this seems to have come to a halt around 2008. I don’t know of any progress on 4 and 5. The 2007 Technology Roadmap for Productive Nanosystems from Battelle and the Foresight Nanotech Institute has a good list of things that need to be done to achieve progress with a number of different approaches to making functional nanoscale systems, including MNT approaches, but it does not go into a great deal of detail about how to do them.

In the remainder of the interview, Prof. Jones explains what he means by “soft machines” and describes his current work in the area. He also comments on advances in nanotechnology, on the rate of technology advancement in general, on investment bubbles, on prospects for near-term nanotechnology in various fields, and on things to fear from the development of nanotechnology. His biggest fear: “But rather than worrying about runaway technology, my biggest fear now is the opposite — that we won’t devote enough resources to get the innovation we need.” On this last point, I personally have to agree completely. Other excellent items for further thought:

… But history seems to suggest that having more advanced technologies makes societies less, not more, equal. Access to new technologies gives access to power, and people don’t seem very good at sharing power. …

In the past we had many laboratories (in both the private sector and the public sector) that connected basic science to the people who could convert technological innovations into new processes and products — one thinks in the USA of great institutions like Bell Laboratories. These applied technology labs have been run down or liquidated, and their place has not been fully taken by the new world of spin-outs and venture capital backed start-ups, whose time horizons are too short to develop truly radical innovations in the material and biological realms. So we need to do something to fill that gap. …

On these and other points, I would recommend the interview as very well worth reading in full. As to Prof. Jones’s view on the difficulty of implementing MNT as it was presented in Nanosystems, the issues he raises remain largely unanswered. The Roadmap for Productive Nanosystems was released nearly seven years ago, and was only a first step toward a complete roadmap, and to my knowledge it has not been extended or updated. The progress with soft nanomachines, especially in structural DNA nanotechnology, has been substantial, but no one has published a detailed implementation path by which such progress could be extended to making and breaking covalent bonds with atomic precision, and from there to nanofactories capable of general purpose atomically precise manufacturing. There is much to be done, and the necessary investment is, to my knowledge, nowhere in sight.
—James Lewis, PhD

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