MEMS Surface Coating Condition Monitoring via Nonlinear Tapping of Resoswitches

Abstract

A MEMS resoswitch-enabled surface coating condition-monitoring device is demonstrated as a proof of concept that successfully detects the existence of molecule coated on the structure surface. In particular, a CMOS-MEMS clamped-clamped beam (CC-beam) resoswitch exhibits a distinguishable change in the tapping bandwidth of the frequency response against different surface conditions while operating in the nonlinear cold switching mode. By salinizing the surface with (1H, 1H, 2H, 2H)-per-fluorodecyltrichlorosilane (CF3 (CF2)7(CH2)2SiCl3, FDTS), the resoswitch presents a tapping bandwidth extended from 17.37 kHz to 29.75 kHz due to lowered adhesion forces. The resoswitch-based surface condition could be employed to enable in situ monitoring of, for example, the anti-stiction coating often used in MEMS motion sensors.