Nanorobotics: Atomic lattices as gears

In the future, machines will be of molecular dimensions. What forms will such machines take? What are the limits on the sizes of the basic machine elements and the fundamental interactions that govern energy cost of machine motion? We are beginning to answer these questions through the study of the interaction between two bodies in contact at the molecular scale. Understanding how these interactions affect energy loss and object motion is important for designing lubrication strategies and self-assembly processes, and will determine the forms of atomic-scale actuating devices. Aiding these studies is an advanced user interface for the nanoscale, the nanoManipulator. This project, a collaboration between computer scientists and physicists, allows a user to put their hand into contact with the nanometer scale world. After a brief description of this tool and its applications to biophysics, I will discuss our studies of carbon nanotubes with diameters from 30nm down to 1 nm. Our quantitative manipulations of nanotubes reveals that nanotubes bend, slide and translate much like a macroscopic object. However, a surprise awaits when the nanotubes are placed on graphite. They roll. We report, through experimental observations and computer simulations, that atomic lattice interlocking can determine whether an object rolls or slides on a surface. In essence, the atomic lattice is acting like a gear mechanism.