Positional stability of some diamondoid and
graphitic nanomechanical structures:
A molecular dynamics study
Royal Melbourne Institute of Technology
and Oak Ridge National Laboratory
This is an abstract
for a talk to be given at the
Fifth
Foresight Conference on Molecular Nanotechnology.
The full paper is available at
http://www.cs.rmit.edu.au/~gl/research/nano/nano97/index.html.
Molecular dynamics simulations indicate positional stability
to be an important issue in a wide variety of molecular
nanotechnology applications. It can determine the difference
between the success and failure of mechanical nanodevice designs.
Diamondoid materials are proposed for many such designs in part
because diamond is stiffer, stronger and lighter than most other
materials. These properties should allow the problems of
positional stability to be minimized while simultaneously
minimizing atom count (bulk, molecular weight, etc.). Because of
their synthetic availability and desirable mechanical properties,
graphitic materials, in particular carbon nanotubes and
buckyballs, are also components in many proposed nanomachine
designs.
We present results of a molecular dynamics study of the
positional stability of several diamondoid and carbon nanotube
structures, including comparing similar functional designs made
from both these materials. In particular, we investigate tubular
and solid ``struts'' --- which, for example, could form part of
the linear actuators required in a Stewart platform molecular
positioning device --- and simple bearings composed of concentric
carbon nanotube and diamondoid tubes. The effects of shearing,
stretching, and other external forces on positional stability and
nanomachine performance are examined. Finally, quantum mechanical
results for some of these structures are compared with molecular
dynamics results.
Research sponsored by the Division of Materials Sciences,
Office of Basic Energy Sciences, U.S. Department of Energy under
contract DE-AC05-96OR22464 with Lockheed-Martin Energy Research
Corp.
*Corresponding Address:
Goeff Leach, Royal Melbourne
Institute of Technology Department of Computer Science, 124
LaTrobe St., Melbourne, Victoria 3000, Australia, ph: +61 3 9660
3207, fax: +61 3 9662 1617, email: [email protected]
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