Wide-band piezoresistive microphone for aero-acoustic applications

A surface micro-machined microphone employing recrystallized metal-induced-laterally crystallized (RC-MILC) polycrystalline silicon (Poly-Si) piezoresistor is developed for aero-acoustic applications. A static sensitivity of ~0.4μV/V/Pa is measured using a nano-indentation technique and a useful bandwidth starting from ~100kHz with a resonance peak at ~400kHz has been obtained using shock waves generated using a the high-voltage electrical spark discharge.