A Multifunctional Piezoelectric MEMS Actuator for Tweeter and Ultrasonic Range-Finding Transmitter

Nowadays there is a growing demand for smart devices to offer more integrated functions. In this work, a multifunctional piezoelectric MEMS actuator is designed as tweeter and ultrasonic range-finding transmitter at the same time. The actuator achieves a sound pressure level (SPL) of above 70 dB at tweeter frequency range at 10 cm distance in free field. And it adopts a high-order resonance mode at 32.5 kHz to further boost ultrasound SPL of 83 dB. Range-finding of up to 1.6 m is realized working with a MEMS microphone. The distance measurement result has a good linearity with R<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> of 0.999.