μg-level bias stability of a tri-axial grating Talbot-effect-based MOEMS accelerometer

With the advantage of high-precision and anti-electromagnetic interference, micro-opto-electro-mechanical system (MOEMS) accelerometers have significant applications in inertial navigation, the automotive industry, and attitude reference. The cross-axis interference of the accelerometer has seriously affected the accuracy of acceleration measurements. This paper presents a three-axis integrated grating MOEMS accelerometer, featuring lower cross-axis interference and higher bias stability. To minimize cross-axis interference in the tri-axial integration, we designed out-of-plane and in-plane accelerometers featuring a symmetrical cantilever beam structure. Reducing cross-axis interference helps mitigate the effects of disturbances and asymmetric torque, thereby enhancing the bias stability of the accelerometer. Experimental results indicate that the proposed MOEMS accelerometer achieved bias stabilities of 1.14, 2.4, and 1.79 µg on the X, Y, and Z axes, and sensitivities of 7.12, 7.04, and 26.31 V/g (1g=9.81m/s²), respectively. Compared to our former prototype, the cross-axis interference for the out-of-plane detection decreases from 5.02%/1.2g to 0.14%/1.2g, which is an order of magnitude of improvement over previous work.