A Novel Resonant MEMS Accelerometer Operating in Air with Thermally Actuated Piezoresistive Resonators

This paper presents an innovative resonant microelectromechanical system (MEMS) accelerometer that operates effectively under atmospheric pressure. It utilizes thermally actuated piezoresistive resonators as the core transduction element for both excitation and sensing. To enhance sensitivity, an optimized lever system is integrated to amplify the inertial force resulting from acceleration input on the resonators. The resonators consist of two piezoresistive nano-beams that are thermally actuated in air, exhibiting a quality factor of 1723 and a resonant frequency of approximately 1.712 MHz. Moreover, the utilization of two resonators enables a differential sensing scheme for acceleration input, effectively mitigating the influence of ambient temperature fluctuations. Experimental findings demonstrate that the proposed resonant MEMS accelerometer achieves a sensitivity of 572 Hz/g. This novel sensing principle holds promise for diverse applications in the realm of resonant MEMS sensors, encompassing MEMS accelerometers and gyroscopes.