Research on an electrostatic repulsive-force based vertical micro actuator

A structure of micro actuator based on electrostatic repulsive-force is presented to achieve a vertical stroke. Compared with traditional electrostatic attractive-force based micro actuator, its stroke is neither limited by the pull-in instability nor limited by the thickness of sacrificial layer. Numerical simulations are performed to investigate the relationship between the repulsive-force and the structural parameters. Simulation results show that the repulsive-force is highly dependent on fixed finger width, movable finger width, fixed/movable finger width ratio and finger distance.