Mechanical and Environmental Degradation of Self-Assembled Monolayer Coatings for Microelectromechanical Systems

Self-assembled monolayer coatings have shown great promise for dramatically reducing the tribological forces of adhesion and friction in microelectro-mechanical systems (MEMS). However, monolayer coatings often display significant degradation when exposed to extreme environments, dynamic sliding contact, and dynamic impact loading. This degradation is coupled with a corresponding increase in the tribological properties. In this study, the degradation of tridecafluorotri(dimethylamino)silane is examined under the typical operating conditions of MEMS technology using a specialized microdevice designed for characterizing the tribological behavior surface micromachines. Results of friction and adhesion degradation under normal loading and sliding contact are interpreted in relation to the primary degradation mechanisms of self-assembled monolayers.