Thermal Stress Minimization for Torsional Pendulum MEMS Gyroscopes via Center-Supported Structural Design

The bias stability remains one of the most critical performance metrics for microelectromechanical system (MEMS) gyroscopes. However, the inherent thermal stress in MEMS gyroscopes induces resonant frequency shifts and static capacitance variations, which ultimately results in bias drift and thus degrades their accuracy and stability. Here, this work proposes a thermal stress minimization strategy for torsional pendulum MEMS gyroscopes via center-supported structural design. The reported MEMS gyroscope consists of two proof masses (PMs), an outer coupling frame (CF), and multiple folded-beam springs, which are suspended by two anchors positioned at the center of the device structure. This center-supported structural design exhibits lower sensitivity to thermal stress and thermal stress variations. This is because the significant thermal stress arising from the thermal mismatch between the MEMS gyroscope and the package cannot be efficiently transmitted through the center supports. Measurement results indicate that the center-supported MEMS gyroscope achieves an uncompensated bias stability of 0.18°/s and a compensated bias stability of 0.014°/s across the full-industrial temperature range. This work presents a novel approach to mitigate thermal-stress-induced effects in MEMS gyroscopes.