Finite element modelling and simulation of thermo-elastical damping of MEMS vibrations

The contribution is directed to providing accurate simulation and approximation of the Q-factor determined by thermal-elastic damping in complex micro-electromechanical (MEM) resonators. The base model created is presented as a system of partial differential equations, which describe the elastic and thermal phenomena in the MEM structure. The FEM calculations were performed by using COMSOL Multiphysics software. The model was verified by comparing numerically and analytically obtained damped modal properties of a MEM cantilever resonator. The comparison of calculated and experimentally obtained resonant frequencies and Q-factor values indicated a good agreement of tendencies of change of the quantities against temperature. Investigation of longitudinal and bending vibration modes in 3D of a beam resonators was accomplished by taking into account the layered structure of the resonator and the influence of the geometry of the clamping zone. Modal properties of rectangle- and ring-shaped bulk-mode MEM resonators were examined, too.