A Tri-axial Resonating Beam MEMS Accelerometer

MEMS-based devices have helped in the miniaturization of various transducers, one such being the accelerometer. The current study presents the design and simulation of a MEMS tri-axial resonance-based accelerometer in a differential arrangement to measure acceleration up to 5 g. The final tri-axial accelerometer differential design is derived from five designs which consist of four proof masses, four resonating beams, two vertical and two horizontal hinges. The first three designs are non-differential designs and the next two designs give a differential output only for out-of-plane acceleration. Numerical simulations were carried out in COMSOL Multiphysics for all the designs and the dimensions were optimized to obtain maximum stress on the resonating beam for an applied acceleration. Eigenfrequency analysis was also carried out to estimate the change in resonance frequencies of all the resonating beams in each of the proposed models along with the final differential design. The sensitivities were found to be 33 Hz/g, 33 Hz/g, and 19 Hz/g for the final differential design in X, Y, and Z directions respectively. The differential arrangement will be able to compensate for any temperature variations and the resonance condition can be achieved by piezoelectric excitation and detection.