Electromechanical Modeling and Characterization of the Electrical Breakdown for the Capacitive Micro-arrayed Ultrasonic Transducers

This paper presents two numerical evaluation schemes to simulate the dielectric breakdown phenomena for the capacitive micro-arrayed ultrasonic transducers (CMUT). The performance of dielectric strength was investigated using a commercial finite element method (FEM) software package of ANSYS. The electro-mechanical model was established using the ANSYS parametric design language (APDL) technique. A built-in Multiphysics solver of ANSYS was employed for the simulation of the electrostatic-structural coupled-field problems. Relationships of the applied DC bias voltage versus the membrane deflection, collapse voltage, capacitance, and layer-wised electric field distribution are obtained. For a verification purpose, a simple semi-analytical approach based on the classical thin plate theory and parallel-plate capacitor principle was also proposed. Reasonable matching results and less computation efforts are obtained. The proposed approach provides another efficient numerical tool for estimating the dielectric breakdown possibility of the CMUT.