Study of Parameters and Characteristics of MEMS Capacitive Accelerometer with Vertical Overlap Comb Drive Construction

Today micromechanical capacitive accelerometers with comb drive constructions are intensively developed. A two axis (X and Z) capacitive accelerometer using vertical overlap comb drives structure has been designed. The capacitance changes between the moveable and fixed electrodes and the main influence factors of the sensor have been calculated. The capacitance changes of the proof mass due to X-axis acceleration and Z axis acceleration are equal to 1.372pF and 7.854pF. Mechanical bending stresses of the proof mass due to X and Z acceleration are equal to 31.959MPa and 26.043MPa. The resonant frequencies of the proof mass at working axis (X) and Z are 1026MHz and 1309MHz. Owing to the temperature from -40°C to 80°C, the deformation of the proof almost never occur. The obtained result is a well-reasoned choice of the design and reasonable parameters of micro comb construction actuators with four folded beams.