Molecular Dynamics Simulation of Carbon Nanotube Based Gears
This is an early draft of a paper to appear in the journal Nanotechnology.
The published version is
Jie Han, MRJ, Inc. at NASA Ames Research Center,
MRJ, Inc. at NASA Ames Research Center,
Richard Jaffe, NASA Ames Research Center, and
Sterling Software at NASA Ames Research Center.
We used molecular dynamics to investigate the properties and design
space of molecular gears fashioned from carbon nanotubes with teeth
added via a benzyne reaction known to occur with C60 [Hoke 92]. A
modified, parallelized version of Brenner's potential [Brenner 90] was
used to model interatomic forces within each molecule. A Leonard-Jones
6-12 potential [Allen 87] was used for forces between molecules.
One gear was powered by forcing the
atoms near the end of the buckytube to rotate, and a second gear was
allowed to rotate by keeping the atoms near the end of its buckytube
on a cylinder. The meshing aromatic gear teeth transfer angular
momentum from the powered gear to the driven gear. A number
of gear and gear/shaft configurations were simulated. Cases in vacuum
and with an inert atmosphere were examined. In an extension to
molecular dynamics technology, some simulations used a thermostat on
the atmosphere while the hydrocarbon gear's temperature was allowed to
fluctuate. This models cooling the gears with an atmosphere. Results
suggest that these gears can operate at up to 50-100 gigahertz in
a vacuum or inert atmosphere at room temperature. The failure mode
involves tooth slip, not bond breaking, so failed gears can be
returned to operation by lowering temperature and/or rotation rate.
Videos and atomic
trajectory files in xyz format are presented.
To the full paper.
To companion papers.
Web Work: Al Globus