Vibrational and thermoelastic behavior of punched-beam micro resonators containing odd-number of slots

Abstract

Thermoelastic quality factor is an important mechanism for determining quality factor of a microelectromechanical system resonator, which works in near vacuum, and the resonant frequency is an important characteristic of a resonator. This paper studies variations of the thermoelastic quality factor and the resonant frequency of three- and five-slotted clamped-clamped beam microelectromechanical system resonators. The study has been done by using three-dimensional simulations based on finite element method by COMSOL Multiphysics. Resonant frequency is a function of stiffness and mass of the beam, therefore punching slots in the beam changes the resonant frequency. In addition, slots usually decrease the amount of coupling between mechanical resonant mode and thermal modes, thus improve the thermoelastic quality factor. The C–C beam lengths are considered to be 30.5 µm, 100 µm, and 400 µm. The results show the resonant frequency and corresponding thermoelastic quality factor of the three-slotted beams are greater than five-slotted beams, and a maximum resonant frequency of the three-slotted beams is achieved when the length of inner slot is about 32%–36% of the beam length.