For the penultimate talk we have Eric Drexler, introduced by Bill Goddard as “grandfather of nanotechnology”. Topic is “Design and Analysis of a Molecular Tool for Carbon Transfer in Mechanosynthesis”. Name of the tool is DC10c. There are multiple paths forward toward artificial molecular machinery made of strong covalent solids. Slide shows stages of nanotechnology, from evolving technologies through Class 4 systems; this is from the Technology Roadmap for Productive Nanosystems. Now giving advertisement for benefits of using proteins, often called soft; now humorously showing a hard protein object, a very hard horn. (Laughter)
Motivation for the work: advanced mechanosynthesis will require the binding and transfer of highly reactive moieties, need transfer to be highly reliable. Screened many structures using AM1, then quantum chemistry techniques to narrow down, then later DFT methods. Now showing the molecular design of this DC10c dimer transfer tool (there’s a journal ref for this on the screen but I can’t read it from back here). The dimer tip is well-exposed (I think this deals with the “fat finger” concern.) Now a diagram showing this tip making a new transfer to a (9,1) nanotube. Eventual use: machine phase systems.
Failure analysis and reliability. Note: in liquids, energy differences of kT can make a big difference. In machine phase systems, reactive moeities cannot meet and so results are much less sensitive to small errors in the modeling. Current design is for room temp, small errors would lead to having to operate at lower temps, or could tolerate lower reliability. Different problem is unimolecular failure modes. Slides shows examples of these failure modes. For more info, see the journal article.
There are now some great questions and answers, but it’s moving too fast for me. Apologies for any errors or omissions.—Christine
