A Piezoelectric MEMS Loudspeaker Lumped and FEM models

Abstract

This paper presents the simulation results of a piezoelectric MEMS loudspeaker. The micro-fabricated device is composed of two wafers, the first one featuring two bending piezoelectric actuators with large displacements, and the other one featuring a mobile rigid plate surrounded by a small interstice providing a thermoviscous layer hence avoiding an acoustic short-cut between its front and back sides. The current design allows a radiated pressure of 80 dB <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SPL</sub> from 1 <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">kHz</i> at 10 cm and at 30 Volts for a 64 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> footprint, which is above the known performances of the state of the art for MEMS loudspeakers with such dimensions.