Lubrication and Tribological Performance Optimizations for Micro-Electro-Mechanical Systems

Abstract

Two approaches to solving MEMS tribology problems have been pursued. In the first approach, a direct lubrication method using well-known lubricants such as perfluoropolyether (PFPE) and multiply alkylated cyclopentane (MAC) was developed. Extensive tribological tests using reciprocating sliding and actual MEMS tribometry were conducted. The second approach utilized the concept of hydrodynamic lubrication and selective surface modification for MEMS. In the interests of fluid-film liquid lubrication of MEMS, MAC was found to reduce the hydrodynamic friction of high-sliding MEMS when included as an additive in hexadecane at an optimum concentration. This phenomenon is believed to be due to the ?half wetted bearing? effect and not due to the change in viscosity. A compound blend of octadecylamine and MAC additives in hexadecane was found to reduce both boundary and hydrodynamic friction. Anti spreading methods using additives were finally investigated to prevent starvation.