Impact of dimensionless length scale parameter on material dependent thermoelastic attenuation and study of frequency shifts of rectangular microplate resonators

Abstract

Quality factor is one of the decisive performance parameters of micro/nano plate resonators based sensors and filters .Various energy dissipation mechanisms limit the maximum attainable quality factor, and in micro/nano scales thermoelastic damping is a critical energy loss mechanism. When the devices are scaled down, in order to accurately model micro/nano scale resonators, non-classical elasticity theories like Modified Couple Stress Theory (MCST) are valid. In this paper, by including a length scale parameter (l) the size effects were incorporated in the analysis and thermoelastic energy dissipation and related attenuation were found to be diminished by selecting a dimensionless length scale parameter i.e. l/h. Thermoelastic attenuation and frequency shifts related to thermoelastic damping in microplate rectangular resonators with five structural materials (SiC, polySi, diamond, Si and GaAs) were investigated with l/h =0.The attenuation related to thermoelastic energy dissipation and frequency shifts were found to be minimum for polySi material. With the inclusion of size effect, the impact of dimensionless length scale parameter on thermoelastic attenuation of polySi based microplate resonators was also explored. The conventional thermoelastic damping analysis in rectangular plate was modified by applying Modified Couple Stress Theory and the impact of dimensionless length scale (l/h) on thermoelastic energy attenuation was simulated numerically using MATLAB 2015.