The Study of Parameters of the Sensitive Element of the Capacitive Microaccelerometer with Sandwich Construction

This paper focuses on the study of sandwich-type sensitive elements with folded springs of a capacitive micromechanical accelerometer. Larger gaps (up to 20 microns) between the movable and fixed electrodes simplify the manufacturing technology. The optimized design of the sensing element (compared with analogs [1]) ensures high sensitivity. The study reveals that the change in capacitance caused by acceleration along the working axis (Z) is almost 20 times as big as the changes in capacitance along other axes (X and Y). The effect of temperature within the range from -40 °C to + 85 °C on the change of capacitance along the working axis (Z) is small ±0.0025 – 0.003pF. The mechanical stresses that occur in the sensitive element structures at the acceleration of up to 50g do not exceed 2.29MPa, while silicon has a mechanical strength of 440MPa.