First, new designs for repulsive-force electrostatic actuators (RFAs) were fabricated and evaluated, including: 2-layer linear and rotary RFAs, multi-layer RFAs for increased stroke, and RFAs with work-optimized electrode geometries. Second, a new bidirectional repulsive-/attractive-force electrostatic actuator (RAFA) was introduced, which employs the RFA electrode patterns but can controllably generate either repulsive or attractive forces by simply varying two input voltages. Third, a flexible, 8-fingered robotic gripper was developed, which employs electrostatic adhesion to grasp and manipulate flexible films (such as satellite multi-layer insulation).
RFAs exhibit interesting characteristics – including stable open-loop operation and peak force at rest – and are compatible with thin-film / planar manufacturing processes. Demonstrated applications include RFA-powered 1- and 2-DoF micro-mirror systems, and a RAFA-powered 132 mg crawling robot.