Characterization of capacitive micromachined ultrasonic transducers

Abstract

This communication describes numerical and experimental characterization of CMUTs for ultrasound transmission. Simulations based on finite elements method to model CMUTs electromechanical behaviour and to determine the dimensions of elementary cells are presented. In particular we analyze the collapse voltage variations for different parameters of a circular cell and the capacitance variations for different bias voltages. We report the deformations of non-metallized and metallized membranes and we determine eigenfrequencies, bandwidth and quality factors of cells. The fabrication of CMUTs is based on the anodic bonding of a SOI wafer on a borosilicate glass substrate and we compare experimental results with numerical results.