Numerical study of impact of surface roughness on thermoelastic loss of micro-resonators

In this work, a numerical investigation on thermoelastic damping (TED) in micro-resonators with surface roughness has been reported. A numerical approach using the finite element method (FEM) is implemented for creating surface roughness on the top and bottom of beam resonators. Quality (Q) factor for fundamental flexural mode is numerically obtained using eigenfrequency analysis. The results of the simulations reveal that the local thermodynamic balance becomes upset in the presence of asperities on the surfaces of the rough resonators and the restoration of this balance is accompanied by many local irreversible heat flow processes that give rise to the bulk TED of the resonator. The effect of the resonator thickness and surface asperity height on the surface QTED is investigated.