Novel Thermal Mems Dynamic Pressure Sensor

This work presents a novel dynamic pressure sensor using micro-thermal structures. The sensor offers the advantage of detecting sound without any moving mechanical structures as in conventional capacitive microphones. It works on the principle of the modulation of heat transfer using an acoustic flow via on-chip micro channels. Different chip designs are fabricated and acoustically characterized.In general, the sensor output voltage shows a quadratic dependence on the input sound pressure in a 74 -114 dB SPL range. The sensor offers almost constant sensitivity in the infrasound region and offers a narrow bandwidth up to around 60 Hz depending on the design.