MEMS absolute pressure sensor on a flexible substrate

This paper describes the fabrication and characterization of micromachined, piezoresistive, absolute pressure sensors sandwiched between a flexible polyimide. The sensors are designed for structural health monitoring in aerospace applications. A suspended aluminum oxide diaphragm is utilized where nichrome (Ni-80%/Cr-20%) piezoresistive sensors are placed in a half Wheatstone bridge geometry to ensure a linear response and thermal stability. The sensitivity was found to be 1.51 nV/Pa with an average dynamic range of 8.31 MPa.