Design and performance analysis of a MEMS Based Area-Variation Capacitive Accelerometer with Readout Circuit

Abstract

The structural optimization of the device is used in the present work to demonstrate the improvement of the device sensitivity for a MEMS accelerometer based on capacitive principle due to overlap area change between electrodes. The proof mass of the device is made up of a few parallel fingers those are joined together. Proof mass is supported by flexible mechanical beams that resemble springs is suspended over fixed electrodes and are fastened to the substrate. The greatest displacement that the proof mass can suffer with application of acceleration is determined for the specific construction. The connected beams' width and length were changed, and ANSYS FEA software was used to model the reaction. Sensitivity of the device is analyzed and discussed based on the findings of various device geometry measurements, and suggestions for improving sensitivity are also made. Additionally, a signal conditioning circuit that changes the capacitance to voltage as a result of the proof mass deflecting differently is described. These discoveries might help designers to create capacitive MEMS accelerometers with increased sensitivity.