Piston-tube electrostatic microactuator

摘要

A three-degrees-of-freedom MEMS electrostatic piston-tube actuator is disclosed. The actuator comprises two structures. A structure that comprises a plurality of fixed piston-like electrodes that are attached to a base, and form the stator of the actuator. A second structure that comprises a plurality of moving tube-like electrodes that are attached to the body of the upper structure and form the rotor of the actuator. The rotor is attached to the stator through a mechanical spring. The rotor of the actuator provides a 3-DOF motion, comprising vertical translation and bi-axial rotation about the axes of the structures. The present piston-tube actuator utilizes a configuration that enables the use of wide area electrodes, and therefore, provides a high output force enabling translation of the rotor or a high output torque enabling rotation of the rotor.

主权项

1. A micro electromechanical system (MEMS) electrostatic actuator, comprising:
a. a stator plate having an x- and y-axis defining an x-y plane, and a z-direction being perpendicular to the x-y plane, said stator plate having
a top surface and a thickness,a stator-support-frame surrounding the stator plate,an array of spaced apart pistons extending upwardly from the top surface of the stator plate, said pistons having vertical piston-walls and a piston-height,wherein said array of pistons comprising of multiple subarrays of pistons,the pistons in each subarray of pistons being electrically connected to each other,the pistons in each subarray of pistons being electrically insulated from the pistons in other subarrays of pistons, andwherein each subarray of pistons being electrically addressable; and b. a rotor plate having
a non-moving rotor-support-frame surrounding the rotor plate, wherein said rotor-support-frame is placed on and attached to said stator-support-frame,an array of spaced apart tubes open on both ends fabricated in the rotor plate, each said tube having a vertical tube-wall and a tube-height, wherein said tubes being vertically aligned with said pistons, and wherein each said tube having a tube opening sized and shaped to receive and interdigitate with each said piston without the piston-walls touching the tube-walls during a rotation,said tubes being electrically connected to each other,a plurality of springs connecting said array of tubes to said non-moving rotor-support-frame, wherein during an actuation in response to electrostatic forces from a drive voltage applied between one or more subarrays of pistons and the rotor plate, the rotor translates along the z-direction and tilts around the two x and y axes, andan actuator-plate located on said rotor plate and surrounded by said tubes, wherein said actuator plate forms a single rigid body with said tubes, and wherein said actuator provides motion with 3 degrees of freedom including one translational and two rotational motions by selectively actuating said subarrays of pistons.