This paper reports on a piezoelectric (PZT) cantilever with Helmholtz resonator (HR) for a sound-triggered wake-up switch which detects a specific frequency tone with low standby power consumption. The size of the cantilever was 1500 μm × 1000 μm × 2 μm. Both resonant frequencies of the cantilever and the HR were designed to be the same in order to improve the output voltage. The sensitivity of the fabricated cantilever with HR was 41 mV/Pa at 2.1 kHz.

References :
Yutaka Tomimatsu, Hidetoshi Takahashi, Takeshi Kobayashi, Kiyoshi Matsumoto, Isao Shimoyama, Toshihiro Itoh, Ryutaro Maeda“A Piezoelectric Cantilever with Helmholtz Resonator for a Sound-Triggered Wake-up Switch,” The 12th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2012), Atlanta, Georgia, USA, Dec. 2 - 5, 2012.