Diamond and polycrystalline diamond for MEMS applications: Simulations and experiments

To date most of the MEMS devices are been based on Silicon. This is due to the technological know-how accumulated on manipulating, machining, manufacturing of Silicon. However, only very few devices involve moving parts. This is because of the rapid wear arising from high friction in these Silicon based systems. Recent tribometric experiments carried out by Gardos on Silicon and polycrystalline diamond show that this rapid wear is caused by a variety of factors, related both to surface chemistry and cohesive energy density of these likely MEMS bearing materials. Therefore, theoretical and tribological characterization of Si and PCD surfaces is essential prior to device fabrication to assure reliable MEMS operation under various atmospheric environments, especially at elevated temperatures. In this paper, we summarize tribological experiments and theoretical studies of friction and wear processes on diamond surfaces. We studied the atomic friction of diamond (100)-surface employing an extended bond-order-dependent potential for hydrocarbon systems in MD simulations.