摘要
One of the key requirements for MEMS speakers is to increase the sound pressure level(SPL)while keeping the size as small as possible.In this paper we present a MEMS speaker based on piezoelectric bimorph cantilevers that produces a higher SPL than conventional unimorph cantilever speakers.The active diaphragm size is 1.4×1.4 mm^(2).The bimorph cantilevers are connected in parallel to make full use of the actuation voltage.At 1 kHz,the measured SPL reached 73 dB and the peak SPL reached 102 dB at the resonance frequency of 10 kHz in a 711 ear simulator under a driving voltage of 10 V_(rms).The total harmonic distortion of the MEMS speaker was less than 3%in the range from 100 Hz to 20 kHz.Although the absolute SPL was not the highest,this work provides a better SPL for all piezoelectric MEMS speakers.
基金
This work was supported by the funding from Natural Science Foundation of China(Grant No.62001322)
the National Key Research and Development Program(Grant No.2020YFB2008800)
the Nanchang Institute for Microtechnology of Tianjin University.
