Design and Fabrication of Ultralow Temperature Vibration Sensor Based on Self-Excited Vibration Resonance Frequency Test

In the field of aerospace, deep space exploration is becoming more and more frequent, and the temperature deep in the universe is getting lower and lower. Specialized equipment for vibration monitoring of instruments under harsh conditions of ultralow temperature is scarce, and how to design a vibration sensor to solve the vibration monitoring in ultralow temperature environments is an urgent problem. In this article, we propose a novel testing methodology known as self-excited vibration resonance frequency test (SEVFT) of piezoelectric sheet in ultralow temperature, which contributes to the ultralow temperature survival verification of piezoelectric materials for ultralow temperature vibration sensors. The method proves that the PZT-7A piezoelectric material can work in ultralow temperature environments. The sensitivity of the ultralow temperature vibration sensor was obtained by vibration test as well as temperature test to be 5.08 mV/g. It can work normally at −197 °C-RT with small output signal noise. The ultralow temperature vibration sensor designed in this article has low cost and good low-temperature resistance. It can be widely used in structural health monitoring of instruments and equipment in ultralow temperature environments.