Performance analysis of a tunable piezoelectric actuator based MEMS resonator

In this paper, the quality factor of a tunable piezoelectric actuator based MEMS resonator is analyzed. The piezoelectric effect is the transfer of electric energy to mechanical energy and vice versa which arises in many crystalline materials. A tunable piezoelectric actuator based resonator consists of a cantilever beam actuated by a piezoelectric device mounted on the beam. A piezoelectric device can actuate a cantilever beam by applying an AC voltage over the device. The cantilever beam itself has resonant modes that causes peaks in the vibration when the frequency of the applied voltage matches the resonance frequency of each mode. If another piezoelectric device is attached to the cantilever, it is possible to tune the resonance by connecting that device to a passive external circuit. The multilayered structure created in a tunable piezoelectric actuator causes a discontinuity in thermal transport across the structure, altering the thermoelastic behaviour of the resonator. Applying the principle of superposition, the overall frequency dependent quality factor of tunable piezoelectric actuator can be calculated and it shows two minima compared to that of simple fixed-fixed beam resonators. The Q Factor analysis of the actuator is done by a high end software COMSOL Multiphysics.