Characterization of Silicon Carbide Pressure Sensors at 800 °C

Initial characterization of MEMS-based single crystal 4H-SiC piezoresistive pressure sensors has been performed to determine the operational reliability over time at 800 °C. Important parameters such as the zero pressure offset, bridge resistance, and pressure sensitivity as affected by temperature were extracted. These parameters showed relative stability within the prescribed operational window of the sensor at 800 °C. Of significance was the increase in pressure sensitivity with increasing temperature beyond 400 °C, to the extent that the sensitivity at 800 °C equal to or higher than the room temperature value. The sensor can, therefore, be inserted further into the higher temperature section of the test article, thereby making it possible to capture higher frequency bandwidths of the thermoacoustic instabilities, which is critical for the validation of computational fluid dynamics predictive models.