A micromachined gas inertial sensor based on thermal expansion

Thermal expansion in volume is a natural phenomenon as a result of change in temperature. However, it is used rarely as an actuating source of movement in macrocosm due to its weak motion. In this paper we propose to utilize a gas thermal expansion in microcosm to generate seismic gaseous mass for sensing inertial quantities including angular rate and acceleration. The expansion-based inertial sensor possesses the advantages of simple structure, low fabrication cost, high shock resistance, large-range rotation gauge, and low coupling between rotation and acceleration. We present the theory principle for applying thermal expansion to inertial sensor, and conduct the validation of simulations and experiments on the new sensor. The results indicate that the sensor with a tailor-made read-out circuit is effective to simultaneously detect both of the Z-axis rotation and the Y-axis acceleration, and exhibits a good linearity of angular rate output with respect to a large-range rotation of ±3000°/s.