Analysis of the Suspension Elements for the Sensitive Element of a Micromechanical Accelerometer

Abstract

Modern designs of sensitive elements of many MEMS, including micromechanical accelerometers, contain suspension elements, with the help of which the inertial mass is connected to a fixed frame. The simulation was carried out using the ANSYS program, the parameters and characteristics of the sensitive element of a micromechanical accelerometer with suspension elements of various designs made of silicon with different crystallographic orientations were investigated, and the values of their most important parameters were obtained. The natural frequencies of oscillations of the inertial mass, the residual mechanical stress in the structural elements of the sensitive element of the micromechanical accelerometer were calculated. Changes in the natural vibration frequency and residual mechanical stress in the suspension elements were determined when the temperature changed from +150 to –150 ° C in a short time interval (10 s). The change in the residual mechanical stress of the inertial mass of the sensitive element during impact was investigated. The results obtained made it possible to develop recommendations for choosing the design of a sensitive element with silicon suspension elements, which provide high sensitivity and stability of the parameters of a micromechanical accelerometer. The results obtained will be useful in the development of real designs of MEMS sensitive elements with optimal and stable parameters.