The Evolution of Nanomachinery

csy writes: "Harvard's George Whitesides has a wonderful article on Nanomachinery in this month's issue of Scientific American. He casts doubts on the Drexlerian vision of mechanical assemblers, and argues that biology and chemistry, rather than mechanical engineering point to the answers in the quest for nanomachines."

Comments

Even smaller scale though?

[apsmith]

The article talks about the machinery of cells as an example of existing nano-machinery on which we should base the development of artificial nano-machines - but the proteins and other bio-molecules in a cell are actually pretty large compared to some of the things we can do even now with STM microscope tips and carbon nanotubes. Even the smallest virus is 0.05 microns across, and we're already regularly making semiconductor components on that scale. Admittedly the virus has some complex internal structure. But biology uses a very limited set of chemical elements (mainly C, H, O, N) and I think one of the main ideas with nano-machines was that there's no need to restrict yourself to the limited set of things used in biology...

Existance proofs

[steveha]

This article contained a lot of straw-man attacks against Drexler's ideas. But it missed the point. K. Eric Drexler never said that his vision of little mechanical machines is the only way to go about things.

For example, Drexler focused on mechanical computers, with little rods moving back and forth. Does he think nanoscale quantum computers, driven by electricity, can never work? No, but for his book he wanted to focus on things he could be sure would work. Because nature includes little machines, he was sure you could use little machines to build things like tiny computers.

His first book, Engines of Creation, is pretty much about existance proofs. He figures you can probably make an assembler with just 150 million atoms, so then he assumes it will take a billion atoms (just to be on the safe side) for the rest of the discussion.

And in his discussion of how we will get these magic assemblers, he said that one possible route was biological: use tailored cells to make new cells that are closer to what we want, and iterate. He isn't ignoring biology, or reality.

The article is weak. Read Drexler's book instead; it's online so you can read it now for free.

Engines of Creation

steveha