Molecular Dynamics Simulations of
Carbon Nanotubule Bending and
the affect on Electrical Properties
This is an abstract
for a talk to be given at the
Fifth
Foresight Conference on Molecular Nanotechnology.
There will be a link from here to the full article when it is
available on the web.
One potential application of the carbon nanotubule is in
nanoscale mechanical sensors, e.g. nano-vibration gages, strain
gages, etc. This paper discusses two aspects important to the
development of such devices. Since the discovery of carbon-based
nanotubules by Iijima, many theoretical and experimental studies
of the electronic and mechanical properties of tubules have been
conducted. Currently, experimental work is being conducted at the
University of North Carolina-Chapel Hill using the 'Nano-Manipulator',
a virtual-reality enhanced atomic force microscope. The
microscope is being used to bend large multi-walled tubules.
Tubes in the bent state exhibit a series of kinks in the region
of the bend. Molecular dynamics simulations are used to provide
insight into the dynamics of bending and to explain the existence
of multiple kinks in the bent state. In the simulation, a 2000
atom single-walled carbon nanotublue is bent to approximately 60
degrees and then allowed to relax. The simulations show that many
kinks form early and coalesce to form a few larger kinks, similar
to what is seen in experiment. Stress analysis within the tubule
is used to understand these results.
The change in electrical properties in the tubes as a function
of deformation must also be understood in order to develop nano-
sensors. The relative electrical conductivity between pristine
and kinked tubules has been investigated using tight-binding
calculations. Future work will involve bridging the experimental
/ theoretical gap by utilizing increased computational power and
parallel processing to increase the size of computational models
as well as decreasing the size of tubules used in experiment by
the UNC group.
aSupported by the NASA-Ames Computational
Nanotechnology Program
bSupported by the National Science
Foundation
cSupported by the National Institutes of
Health
*Corresponding Address:
Donald W.
Brenner, Associate Professor, Department of Materials Science
and Engineering, Department of Chemistry, Campus Box 7907, North
Carolina State University, Raleigh, NC 27695-7907, ph:
919-515-1338, fax: 919-515-7724, email: [email protected]
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