Temperature and Relative Humidity Dependence of Quality Factors of MEMS Cantilever Resonators in Atmospheric Pressure

摘要

In this study, the effects of temperature (T) and relative humidity (RH) of moist airare discussed on the quality factors (Q-factor) of micro-electro-mechanical-system(MEMS) cantilever resonators in atmospheric pressure (p = 101,325 Pa). The dominantsqueeze film damping (SFD) of MEMS cantilever resonators is studied by solvingthe modified molecular gas lubrication (MMGL) equation. Dynamic viscosityand Poiseuille flow rate of moist air are utilized to modify the MMGL equation asfunctions of temperature and relative humidity for wide range of accommodationcoefficients (ACs). In atmospheric pressure, dynamic viscosity changes more significantlywith temperature and relative humidity than that of Poiseuille flow rate. Thedominant thermoelastic damping (TED) and support loss are also included to obtainthe Q-factor in wide range of cantilever sizes (length, width, and thickness). Thus,dependence of Q-factors of MEMS cantilever resonators on temperature and relativehumidity is discussed for wide range of ACs and cantilever sizes in atmosphericpressure. The results show that Q-factor could be increase at higher temperature andrelative humidity or lower ACs. Dependence of Q-factor on temperature and relativehumidity enhances considerably in greater length, greater width, and smaller thicknessof cantilever. Maximum Q-factors with temperature and relative humidity canbe obtained for wide range of ACs and cantilever sizes in atmospheric pressure.