A monolithic integrated micromachined piezoresistive flow sensor

In this paper, a monolithic integrated piezoresistive flow sensor is presented, which was fabricated with an intermediate CMOS MEMS process compatible with pressure sensors. Four symmetrically arranged silicon diaphragms with piezoresistors on them are used to sense the drag force induced by the input gas flow. Signal conditioning CMOS circuit with temperature compensation was designed and tested, the resulting temperature coefficient is 6%FS/100degC. The integrated flow sensor was packaged and tested, and the resolution is less than 0.1 L/min with range of 0.1-5 L/min.