Finite element analysis of air-coupled dual electrode bimorph piezoelectric micromachined ultrasonic transducers
This paper presents the three-dimensional finite element analysis of an air-coupled dual electrode bimorph (DEB) piezoelectric micromachined ultrasonic transducer (pMUT). In this study, we aim to create a pMUT geometry design that can be used for rangefinding and motion sensing, i.e., the fundamental resonant frequency must range from 40 kHz to 800 kHz. Using COMSOL Multiphysics, the resonant frequency of the DEB pMUT is determined. Our results show that our selected geometry design produces fundamental resonant frequencies that are within the desired frequency range. Furthermore, we demonstrated here the effects of changing the diaphragm radius and the thickness of the active piezoelectric layer. We also presented in this paper the center displacement and the acoustic performance of the DEB pMUT.