Modeling and Optimization of MEMS Comb-Type Capacitive Acceleration Sensor

The MEMS capacitive acceleration sensors measure acceleration in a wide frequency range and are characterized by a relatively simple construction, considerable stability, low energy consumption, and high X-, Y-, and Z-direction sensitivity. In this study, the results of modeling and optimizing the sensing element of a MEMS comb-type capacitive acceleration sensor are presented. The deformation, resonant frequencies, and capacitance changes in a MEMS comb-type capacitive acceleration sensor with a 30-μm silicon wafer are examined using the Ansys and Ansys Maxwell simulation software based on the finite element method. The sensing element deformation along the X and Y axes is studied, as it plays a critical role in measuring the capacitance of the structure of MEMS comb-type acceleration sensors on exposure to accelerations in the range of 100–500 g. As a result of modeling a MEMS sensor with a different number of combs, changes in the capacitance between the combs are obtained. It is established that the design of a MEMS comb-type capacitive acceleration sensor with 20 pairs of electrodes is optimal in terms of the sensitivity, weight, and size parameters.