Quantitative Detection and Warning of T-Shaped MEMS Resonant Accelerometer Based on Modal Coupling

The article reports for the first time a distributed electrostatic-driven T-shaped micro-electromechanical system (MEMS) resonant accelerometer based on the modal coupling phenomenon. Experiments show that the bifurcation phenomenon induced by modal coupling has great potential in both quantitative detection and warning of accelerometers. First, a distributed electrostatic-driven T-shaped resonant accelerometer with 1:2 modal coupling is designed, and the parametric vibration of the low-frequency resonant vertical beam is realized by driving the high-frequency resonant horizontal beam, which leads to the energy transfer between two modes. The theoretical and experimental results show that the regulation voltage plays an important role in the modal coupling phenomenon. Compared with the traditional resonant accelerometer sensing principle, the sensitivity of the accelerometer can be increased by 5.6 times based on bifurcation phenomenon induced by modal coupling. Typically, a novel acceleration warning scheme based on modal coupling is proposed. Considering the regulation voltage of 220 V and the ac drive voltage of 450 mV, the acceleration applied is from −0.5 to 0 g, and then the bifurcation frequency of the vertical beam increases sharply by 1045 Hz. Simultaneously, the experiment explores the adjustment of ac drive voltage to the acceleration warning value. The research results of this article provide theoretical support and an experimental basis for the development of high-performance resonant acceleration sensors.