Thermal fluctuations will be dealt with as computer sim power improves. The critiques might or might not be true for materials with a Young’s Modulus lower than for diamond (a DFT sim would tell). I guess people are confusing the concept of a universal assembler with Mechanosynthesis. The latter might not prove powerful enough to revolutionize SPM manufacture, but Freitas et al’s simulations to date have proven that some deposition reactions would be successful despite…zero point energy.

There is nothing specific in this critique; sophisticated critiques have been delivered in the past and responding to them requires a level of diamond surface chemistry knowledge that is beyond MNT proponents (and perhaps the state of the science too) at present. What are needed are a set of DFT mechanosynthesis sims garnered towards all the reactions necessary to construct a needed product. Say, an UHV filter or the ideal X-bar diamond tool-tip. If one needed product simply turns out to be un-MNTable and can’t be provided in sufficient quantities by some other chemical process, then the economic upside of MNT can be known and realistic “industrial scale-up” (as opposed to research) budget estimates can begin.