A Piezoresistive MEMS Sensor for Acoustic Noise Measurements

A MEMS piezoresistive acoustic sensor has been developed for measurement of jet screech noise. The new sensor was calibrated in the sound field of an air siren. Two sensors with a size of 510 and 710 pm were tested and compared to commercial sensors. The results show that the MEMS sensors are five to eight times more sensitive than the smallest commercially available piezoresistive sensors. Furthermore, the sensors are stable as demonstrated by the agreement between calibrations conducted over two months period. However, the bandwidth of this first generation sensors is somewhat limited by the damping of the diaphragm motion. This effect will be remedied in the next generation sensors through careful minimization of damping effects and increase of the sensors natural