Multi-band asymmetric piezoelectric MEMS microphone inspired by the Ormia Ochracea

A multi-band piezoelectric directional MEMS microphone is demonstrated based on a bio-mimetic design inspired by the parasitoid fly Ormia ochracea, using the PiezoMUMPs multi-user foundry process. The device achieves a directional sound field response within four frequency bands, all lying below 15 kHz. It acts as a pressure gradient microphone with hyper-cardioid polar patterns in all frequency bands, with the measured mechanical sensitivity being in good agreement with acoustic-structural simulations conducted in COMSOL Multiphysics. The maximum experimentally measured acoustic sensitivity of the device is 19.7 mV/Pa, located at a frequency of 7972 Hz and sound incidence normal to the microphone membrane