We do have things that can manipulate objects at the nano-scale. They're called catalysts, and when they're made out of amino acids they're called enzymes, and

We do have things that can manipulate objects at the nano-scale. They're called catalysts, and when they're made out of amino acids they're called enzymes, and you and I are built out of them. Yes, you can assemble molecules with AFM. The problem with this idea is that either (a) the molecules don't stick together at temperatures much above absolute zero, or (b) they do, in which case they might be stable at useful temperatures, in which case it's better to figure out how to get them to self-assemble or to find a catalyst/enzyme that helps them self-assemble. Because your nifty molecule just isn't that nifty if it doesn't exist in quantities of order 1 mole, and 1 mole is... a lot. You just won't believe how vastly mind-bogglingly big 10^23 is. All of which boils down to this: This essay is great, but the meat of it really is in the first paragraph. Nanotech is a euphemism for chemistry and biochemistry. It is 100% possible -- indeed, nanotech is older than any human-invented technology by many orders of magnitude, by definition, because humans are built out of "nanotech" -- but it's all just chemistry. The real question is why the word nanotechnology is so much more fashionable in grant-writing circles than the old words.