As microengineering technology continues to evolve, the design of MicroElectoMechanical System (MEMS)/NanoElectroMechanical System (NEMS) devices is increasingly more sophisticated. At the same time, there is an increased need to investigate the tribologicaly properties of the materials that are likely components in future MEMS/NEMS deviceshas. Carbon nanotubes are candidate materials for use in NEMS because of their high stiffness in the direction of the nanotube axis, low Young's modulus perpendicular to the nanotube axis and relative ease with which they slide against one another in bundles as a result of their van der Waals interaction with each other. Furthermore, nanotubes can resist high compressive and tensile forces prior to failure due to their flexibility. Here we investigate the responses of a bundle of single-walled nanotubes (SWNTs) and filled SWNTs to compressive and shear forces between two hydrogen-terminated sliding diamond surfaces by using classical molecular dynamics simulations. The results elucidate the role of filling on the tribological responses of SWNT bundles. This work is supported by the National Science Foundation under Grant No. EEC-02288390 through the Network for Computational Nanotechnology is carried out in collaboration with Professor Greg Sawyer (University of Florida). Any opinions, findings and conclusions or recomendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation (NSF).

      Proximal probe tips are used to

      Atomistic simulations can provide insight into the mechanistic aspects of the processes.

      The objectives of this study are to

      Polytetrafluoroethylene (PTFE) is a well known solid lubricant and polymer nanocomposites based on PTFE are considered to be promising materials for tribological applications in space. Like other polymer materials, many properties of PTFE depend on morphology. In this study, molecular dynamics simulations are performed to examine the effect of chain configuration on the frictional behavior of PTFE at the molecular level and compared to microtribological studies on aligned transfer films of PTFE. This work is supported by the Air Force MURI program is carried out in collaboration with Professor Greg Sawyer and Professor Simon Phillpot (University of Florida).