Merkle

1. Merkle • Suggests that in not too many decades we should be able to build products with almost every atom in the right place, inexpensively, and consistent with physical law • Two main issues in nanotechnology: • What will molecular manufacturing systems look like? • What can we build today? • Emphasizes the importance of the carbon structure of diamond for nanoscale devices • One application of nanomachines would be in cancer therapy • Proposes a molecular robotic arm to manipulate individual molecules • Hydrogen abstraction tool • Dimer deposition tool • Hydrogen deposition tool • Carbene insertion tool

2. Whitesides • Looks to biology for examples of existing nanoscale machines and self-assembly • Ribosomal RNA • Chloroplasts • Mitochondrion • Flagellar motors • Emphasizes the difficulty of constructing nanoscale machines with a molecular assembler • Friction and sticking (or “stiction”) • Power source • Pincers or jaws must be smaller than the atoms to be manipulated • Carbon atoms bond strongly to their neighbors • It would be an incredible feat to outdesign evolution

3. Opinion • With time, anything may be possible • Modeling after nature may be faster • Whitesides’ ideas seem a lot more practical given our current limitations • Merkle’s ideas seem to require imagination and forward thinking • Current experiments suggest that at least some of both of the scientists’ conceptions deserve consideration • Until nanoscale structures become economically viable, not as much time and money will be spent on research