MEMS lubrication with alcohol vapour

Abstract

The advancement of microelectromechanical systems (MEMS) could enable numerous advanced mechanical and communication technologies. At present, commercial MEMS devices are limited to the ones that have no motion or limited motion without sliding contacts such as linear sliding, hinge motions, rotations, etc. The main limiting factors impeding the inclusion of the full range of mechanical motions are tribological issues associated with adhesion, friction and wear of the devices. To resolve these issues, various types of lubricants and coatings have been developed and applied to MEMS. But the coating approaches have not yet satisfied long term operation requirements necessary for MEMS devices with sliding contacts to be commercially viable. In this review, we introduce a new paradigm in MEMS lubrication: vapour phase lubrication (VPL) with alcohols under equilibrium conditions. Fundamental aspects of alcohol adsorption on silicon oxide surfaces in ambient conditions are addressed and their implications in the reduction of adhesion, friction and more importantly, the prevention of wear, are presented.