High-temperature Vibration Sensor Based on Ba 2 TiSi 2 O 8 Piezoelectric Crystal With Ultra-Stable Sensing Performance up to 650 °C

High-temperature vibration sensors are needed for precise monitoring of dynamic mechanical conditions in aerospace, automotive, and energy-generation-related systems. In this article, a compression-mode vibration sensor was designed and fabricated using a Ba2TiSi2O8 single crystal for structural health monitoring at elevated temperatures (650 °C). The fundamental performance of the sensor was simulated, and the effect of pretightening torques on sensor performance was studied. Sensor performance was characterized as a function of temperature up to 650 °C in a frequency range of 100—600 Hz. The sensitivity of the sensor was found to be on the order of 2.6–2.7 pC/g over the tested frequency and temperature ranges, with variation below 2%. In addition, the sensor was found to maintain ultrastable sensitivity at 650 °C. Thus, it exhibits good sensing capability and high reliability at elevated temperatures.