There has been a lot study showing the application of MicroElectroMechanical systems (MEMS). Nowadays, scientists are breaking the MEMS limits by going into nanotechnology: studies of some NEMS device such as are a nanotweezer or a nano-memory device have shown the potential applications of nanotechnology [1,2].
One of the "bricks" which seem most promising in building NEMS is carbon nanotubes because of their mechanical properties and because they are easy and "costless" to synthesize. These nanotubes could be made of a single shell (single wall carbon nanotube or SWNT) or with several shells (multi-wall carbon nanotubes or MWNT).
Because of the scale of these systems, friction is an important concern when studying NEMS. Their friction can not be neglected because they are submitted to such small forces that could be in the same range as the friction force. However, the experimental measurement of friction is far from easy at the nano-scale and this can explain why only few experimental measurements of the friction have been made and why the measurement of the friction varies from a scale of 1 to 100 [3,4]. Moreover, only the sliding motion has been probed and no experiments has yet been done to measure the rotating friction of nanotube shells.
Our purpose is to study the motion of a double wall carbon
nanotube. In order to study this motion, we will simulate this device
by molecular dynamics. One piece of software available for doing MD simulation,
NAMD, was developed by the Biophysics Group at The Beckman Institute of
Advanced Technology. By running MD simulations, we will see that the motion
of this device is governed by the friction between the walls and the orientation
of the shells.