Design of MEMS capacitive comb accelerometer with perforated proof mass for seismic applications

Abstract

Micro Electro Mechanical System (MEMS) sensors are characterized by their small size, but their performances exceed that of their macro-scale counterparts. The small size of MEMS devices and their integration with microelectronics proves a major advantage. In this paper, a design of MEMS capacitive comb accelerometer for seismology application using COMSOL Multiphysics platform is presented. A seismometer (also known as a seismograph) is a device that is used to measure and record the behavior of seismic waves. With this data, the location and measure of earthquakes can be detected. This seismic device has a large frequency band, compared to traditional geophones and seismographs. In this paper, a study to measure amplitudes and frequencies of vibrations is presented, and the results are analyzed and compared for perforated mass and solid proof mass. The effect of the size of etch hole for perforation is also studied.The displacement sensitivity and capacitive sensitivity of accelerometer are found to be 1.188 × 10-9m/g and 1.093 × 10-21F, respectively.