A finite element analysis of thermoelastic damping in vented MEMS beam resonators

The effect of geometry on thermoelastic damping in micro-beam resonators is evaluated using an eigenvalue formulation and a customized finite element method. The vented clamped–clamped (CC) and clamped-free (CF) beams with square-shaped vents along their centerlines, are both analyzed by the finite element method. The quality factor and the resonant frequency are obtained as functions of various geometrical parameters including the location, number and size of the vents. The numerical results reveal that the addition of vent sections in the clamped end region can significantly increase the quality factor. The maximum improved quality factor as high as 3801 and 2257 times those of the CC and CF solid beams are realized. The methodology presented in this work provides a useful tool in design optimization of micro beam resonators against thermoelastic damping.