An Electrothermal Actuator With Two Degrees of Freedom Serving as the Arm of a MEMS Gripper

In this paper, we present an electrothermal actuator with two degrees of freedom that can achieve independent in-plane and out-of-plane motions. The device is fabricated with the MetalMUMPs, which offers silicon nitride, polysilicon, and nickel as the major structural materials. The electrothermal actuator achieves large movement. The in-plane tip displacement is 82 μm at 0.039 W. The out-of-plane swing of the tip is 18 μm as the applied voltage varies from 0 to 90 V (0 to 0.36 W) and vice versa. A versatile microelectromechanical systems gripper that is capable of 2-D manipulation can be constructed with two such actuators, each of which serves as the gripper arm.