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Feynman’s Path to Nanotech (part 5)

Is it Worth Starting Now?

Surely, you will say, it would have been wonderful if back in 1959 people had taken Feynman seriously and really tried the Feynman path: we’d have the full-fledged paraphernalia of real, live molecular machinery now, with everything ranging from nanofactories to cell-repair machines.

After all, it’s been 50 years. The 10 factor-of-4 scale reductions to make up the factor-of-a-million scale reduction from a meter-scale system with centimeter parts to a micron-scale system with 10-nanometer parts, could have been done at a leisurely 5 years per step — plenty of time to improve tolerances, do experiments, invent new techniques.

But now it’s too late. We have major investment and experimentation and development in nanotech of the bottom-up form. We have Drexler’s PNAS paper telling us that the way to molecular manufacturing is by protein design. We have a wide variety of new techniques with scanning probes to read and modify surfaces at the atomic level. We have DNA origami producing arbitrary patterns and even some 3-D shapes.

Surely by the time a Feynman Path, started now, could get to molecular scale, the existing efforts, including the pathways described in the Roadmap for Productive Nanosystems, would have succeeded, leaving us with a relatively useless millimeter-sized system with 10-micron sized parts?

No — as the old serials would put it, a thousand times no.

  • To begin with, a millimeter-sized system with 10-micron sized parts is far from useless. Imagine current-day MEMS but with the catalog and capabilities of a full machine shop, bearings that worked, sliders, powerful motors, robot arms and hands. The medical applications alone would be staggering.
  • High-precision machining has not stood still since the 50s. In fact, the starting point today might well be millimeter-sized system with 10-micron sized parts. Existing nano-positioning stages have 50 picometer resolution; existing microgrippers can manipulate parts down to 1 micron; electron-beam lithography can cut with precision in the 10-nanometer range.
  • The bottom-up folks are not nearly as close to real nanotech as the impression the nano-hype news gives. When a researcher announces a nano-transistor, it means he poked at nanotubes with an STM for 5 months and got 17 usable structures, of which 3 worked reliably. Richard Jones’ blog post is quite to the point here. It’s like this classic PhD Comic, but with your grandmother investing her life savings in some nanotech startup instead of wearing a tinfoil hat:
    Phd Comix
  • Top-down and bottom-up can meet in the middle. When nanoscientists succeed in making an atomically precise nanogear, for example, it means that when the Feynman Path machines get to that scale, they can take the gear off the shelf instead of having to fabricate it the hard way. In fact it seems likely that the bottom-up approaches will likely be the way parts are made and the top-down the way they’re put together.

I’ll stick my neck out and say at a wild guess that if only bottom-up approaches are pursued, we have 20 years to wait for real nanotech; but if the Feynman Path is actively pursued as well, it could be cut to 10.

5 Responses to “Feynman’s Path to Nanotech (part 5)”

  1. Chris Peterson Says:

    When asked whether bottom-up or top-down approaches will succeed first, I like to say a hybrid approach using both seems most likely. And that goes for the different bottom-up approaches also; why not use whatever works best for a given part of the pathway? We don’t need to bet on just one pathway, especially if they have applications and payoffs along the way.

  2. joachim Says:

    There are a few miss understanding in those comments. First, the molecule gear (Nat. Mat. 2009) mentionned at the end of the comments, the molecule logic gate (CPL, 2009), the measurement of the conductance of a long molecular wire (Science, 2009) and our old molecule wheel barrow (Nanotech, 2001) or our single C60 amplifier (CPL,1997) have not been explored for the bottom up. They have been explored to demonstrate that below the Feynman path, there is another path: the full machine being a single molecule, not a protein or the assembly of many proteins (a molecule machine is not a molecular machine!)R. Feynman was in love of the “prouesse” of the macromolecular engineering of live. (see the book: Nanoscience: the invisible revolution)
    We are now below life. All those concept-molecules like concept-cars in automobile were experimented not to be assembled step by step using top down or bottom up technology. There were experimented to call for the invention of new technologies. For molecule-calculator, this is clearly an atom technology which was not at all at the menue of the “Roadmap for productive nanosystem”. For molecule-vehicule (and not molecular machine), nobody knowns what to do to drive one alone. That’s a fantastic problem. But it is a problem that you can put on equations, not and impossibility.

    It is time to break the ice and consider the Feynman path as one peculiar path like the Aviram-Ratner diode (1974) was a peculiar path to molecular electronics. What we need now, is not to be push by dream or by applications, but to work at the atomic scale to understand the physics there helped by chemistry and to invent new technologies for our experiments or our calculations. After will come the complex of machine.
    C. Joachim
    Feynman 1997 and 2005

  3. MJK Says:

    So where do you see industry going with all of this? What is the trend?

  4. Mark O'Leary Says:

    I share your intuition that top down could halve the time to realise MM.

    Last month over on CRN I asked Chris Phoenix his thoughts on the microscale equivalent to a nanofactory – a microfactory – as I have been convinced for some time that this development could happen quite quickly, would have short term payback, would hasten research, development and acceptance of MM, and reduce the risk of developing MM first.

    Microfactory development would mainly require a refocussing of lots of development already going on in the MEMS and rapid prototyping spaces. In a sense Feynman’s vsion has taken place in a totally unfocussed way down to near the microscale, so why not refocus here as a starting point?

    CP also thought there was possibilities in this space, but was stressing that MM would be much, much more capable. I wouldnt argue otherwise, but looking at it from the here and now, even a microfactory would be a major leap ahead – almost all the manufactured goods around me have functional granularity above the micron level, and I can easily imagine a generalised manufacturing system based on microblocks. If hi-tech mfrs were to get on board and develop functional micro-componentry, then a closed, near-self-replicating system could be built.

    A revolution? Well costs would start out high, so this would selectively replace only low volume mfrg, e.g medical devices. But look around and there is a huge potential in the area of mundane subcomponentry, if not entire mfrg systems. Time to market would be revolutionised by microfactory supplementation.

    And being less idealistic for a moment, microfabbing could embrace the reprap pragamatic approach and utilise liquid moulding / injection, welding, subtractive steps, etc, etc. In fact a microfabber could be a module in a more mundane macrofabber, which would deal with larger OTS shelf componentry and integration.

    Whatever their form, at about the time that microfactories were ramping up, early nanfab could be building more specialised micro-components (as you point out.) Then there is a smooth path to MM a few years later.

  5. joachim Says:

    For MJK
    Before industry, there is knowlegde. We are not advanced enough to call for industrial products yet. We need to create and develop a true Atom Technology before going to product. One clear trend is to succeed to calculate with a single molecule. Then to develop the corresponding interconnection and packaging technology. This is not possible with e beam litho, nano-imprint…all of this is too dirty. We are working on that a lot in Toulouse, in Singapore and in Tsukuba. THe same for molecule mechanics.
    C. Joachim
    Feynman 1997 and 2005

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