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