Aspect Ratio Approximation for Simultaneous Minimization of Cross Axis Sensitivity Along Off-Axes for High-Performance Non-invasive Inertial MEMS

Cross axis sensitivity occurs because of the 3-dimensional effect of the sensor geometry and it is one of the most critical issue in MEMS design. In this paper, the cross axis sensitivity is minimized first by change in sensor geometry and second by using a Wheatstone bridge. The sensor geometry is proposed with necessary aspect ratio approximation so that the cross axis sensitivity in both the off-axes can be reduced simultaneously. The proposed scheme is designed for \(\pm\) 6 g and has a z axis deflection of 2.59 × 10⁻⁷ m. The cross axis sensitivity for aspect ratio of 1:1 is 4.49 μm²/rad and 2.5 μm²/rad along X direction and Y direction respectively. The approximation of the aspect ratio to 1.4:1 minimizes the cross axis sensitivity and giving a value of around 3.5 μm²/rad in both the off-axes. Thus, the aspect ratio approximation corresponds to low and equal off-axes sensitivities. For high-performance applications, further elimination of the off-axis sensitivity is done with the help of Wheatstone bridge circuit.