Electrostatically actuated electromagnetic radiation shutter
Goodwin, S. (2002). IPC No. U.S.Electrostatically actuated electromagnetic radiation shutter (Patent No. 6396620.)
An electromagnetic radiation shutter device driven by electrostatic forces comprises a stationary membrane capable of allowing electromagnetic radiation transmission therethrough, and a first and second flexible membrane comprising an electrode element and at least one biasing element. The first flexible membrane has a fixed portion attached to the underside of the stationary membrane and a distal portion adjacent to the fixed portion and released from the underside of the stationary membrane. The second flexible membrane has a fixed portion attached to the topside of the stationary membrane and a distal portion adjacent to the fixed portion and released from the topside of the stationary membrane. In operation, a voltage differential is established between the electrode element of the first flexible membrane and the electrode element of the second flexible membrane thereby moving the first and second flexible membranes relative to the stationary membrane. In a closed state (i.e. fully activated), the flexible membranes will be generally parallel to the stationary membrane and will be capable of deflecting electromagnetic radiation. In an open state (i.e. no voltage applied), the flexible membranes will generally be fully curled based on biasing in the flexible membranes induced during fabrication and/or imparted by material characteristics.