Speaker
Description
Piezoelectric MEMS speakers are emerging as promising microscale loudspeaker solutions, driven by the increasing demand for smaller, lighter, and more power-efficient audio devices. However, their integration into mass-market products remains challenging, as it requires simultaneously achieving compact size, high acoustic performance, and compatibility with standard fabrication processes.The push–pull actuation scheme has recently been proposed as an effective strategy to enhance performance compared to single-patch actuation. It employs two independent piezoelectric patches on a silicon diaphragm, driven in anti-phase to increase diaphragm displacement and acoustic output.In this work, a numerical investigation of four design iterations with progressively improved acoustic output is presented. Each design explores the interplay between structural compliance, tuned through the number and pattern of 5 μm slits, and the area and placement of the piezoelectric patches. The design variations include outer actuator reshaping, the introduction of curved beam elements, and the progressive extension of the central diaphragm hub.The best-performing architecture achieves a sound pressure level (SPL) exceeding 113 dB SPL in an IEC 60318-4 coupler from 100 Hz onward, with a piezoelectric capacitance of 15 nF. Overall, this study contributes to the development of design guidelines for low-power, high-performance piezoelectric MEMS loudspeakers compatible with standard industrial processes.