A High Dynamic Restoring Force Electrostatic Actuator

A surface-micromachined parallel-plate microelectromechanical systems actuator with a unique dynamic restoring force mechanism to overcome the stiction and electrostatic hold-down issues commonly faced by surface micromachined actuators has been designed and fabricated. This dynamic boost results in a ~4 × increase in the voltage required to hold the actuator down compared with static actuation, implying a ~16 × increase in effective restoring force. The device´s initial pull-in voltage is unaffected. Also, a generalized mass-spring analytical model has been developed to describe the design of the spring suspension with agreement to measured results within 15%.