Research on high-temperature and high-sensitivity indium tin oxide pressure sensor

In the field of aerospace testing, it is critical for pressure sensors to maintain high sensitivity at high temperatures for pressure testing. Based on indium tin oxide (ITO) piezoresistive effect, a high temperature high sensitivity pressure sensor is designed. Firstly, by employing the theory of small deflection bending of circular thin plates and utilizing COMSOL Multiphysics software to model and simulate sensitive components, the influence of sensitive diaphragm size on sensor performance is analyzed, and the optimal parameters are determined. Then, the chip of 30um line width piezoresistors are prepared by photolithographic sputtering stripping process. Finally, the sensor is packaged using an inverted flush structure and tested. The results show that the sensitivity of the sensor is 31.3μV/kPa/mA at 600℃ ambient temperature and 0.5MPa pressure range, which is higher than most of the high temperature piezoresistive pressure sensors. This research provides valuable insights for future development endeavors aimed at enhancing high temperature piezoresistive pressure sensors.