Dynamic and acoustic modeling of capacitive micromachined ultrasonic transducers

The Capacitive Micromachined Ultrasonic Transducers (CMUTs) are a promising alternative to piezoelectric ultrasound transducers. They are constituted by a very large number of silicon membranes electrostatically actuated. We propose an original method to calculate the acoustic pressure emitted by CMUTs by taking into account explicitly the dynamics of each membrane of the network. The electrostatic forces are linearized, the displacements of the membranes are projected on a mechanical modal base and the acoustic pressures are computed via the Rayleigh integral. The method has been validated by comparison with ANSYS for a single cell and a small hexagonal network of 7 cells. Application on a 2D CMUT network shows the interest of such a calculation method.