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
• Merkles 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