Bidirectional bistable microdrive based on electrothermal and electromagnetic drive

Abstract

The invention relates to a bidirectional bistable microdrive based on electrothermal and electromagnetic drive in the technical field of micro electronmechanical system. The bidirectional bistable microdrive based on electrothermal and electromagnetic drive comprises a permanent magnet, a substrate, an electrothermal and electromagnetic drive unit, a bidirectional moving beam unit, mechanical locking units and electric contact units, wherein the permanent magnet is positioned under the substrate and closely connected with the substrate; the electrothermal and electromagnetic drive unit, the bidirectional moving beam unit, the mechanical locking units and the electric contact units are positioned above the substrate respectively; the bidirectional moving beam unit is connected with the electrothermal and electromagnetic drive unit to form a movable beam which is hung in the air and moves freely; a pair of mechanical locking units are symmetrically distributed on both sides of the bidirectional moving beam unit and the electrothermal and electromagnetic drive unit; and a pair of electric contact units are symmetrically distributed at the left end and the right end of the bidirectional moving beam unit. The bidirectional bistable microdrive based on electrothermal and electromagnetic drive has simple process, not only fully represents the perfect combination of MEMS technology and smart mechanical structure but also reasonably utilizes the coordinative and interdependent function of electrothermal and electromagnetic force, and realizes a bistable mechanism without power dissipation.

Description

technical field [0001] The present invention relates to a micro-driver in the technical field of micro-electro-mechanical systems, in particular to a bi-directional bistable micro-driver based on electrothermal electromagnetic drive. Background technique [0002] The two most important features of micro-electromechanical systems (MEMS) are micro-sensors and micro-drivers. As a part of the most important core technology in MEMS, micro-drivers have become the focus of research in recent years on their driving mechanism and the preparation of prototype devices. The driving mechanism of the micro-drive mainly uses various physical effects. Typical driving mechanisms include electrostatic drive, electromagnetic drive, electrothermal drive, piezoelectric drive, etc. Although the electrostatically driven MEMS micro-driver has a simple structure and low power consumption, the electrostatic drive voltage required to maintain good working performance is high. ) process is not compati...

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Problems solved by technology

[0004] Found through literature retrieval to prior art, the title "A NovelBistable Two-Way Actuated Out-of-Plane Electrothermal Microbridge" ("A new bi-stable bi-stable electrothermal driver"), the literature report proposed a new type of bi-stable bi-stable electrothermal driver, the design uses a bridge-type out-of-plane motion, and the electrothermal drive part is made of Composed of curved beams supported by springs and brackets, while springs and brackets are made of Si / SiO 2 / SiO 2 The three-layer structure, when the driving voltage is 9V, the out-of-plane displacement of 31 μm can be generated when the bridge length is 1200 μm, which shows that its driving efficiency is relatively low

At the same time, due to the spring stiffness and the thermal stress of the bracket to make the beam bend, the driving force is obviously very small, and the bending beam is prone to fatigue damage, resulting in limited life, and the thermal drive response is slow, which is not enough to quickly control the effect of the external circuit switch

[0005] In addition, Weisong Wang et al published the title "Design of a bidirectional MEMSactuator with high displacement resolution, large driving force and power-free latching" on "Microelectronic Engineering" ("Microelectronics Engineering"), No. 85, pp. 587-598, 2008 ("A bidirectional MEMS micro-actuator with high displacement resolution, large driving force and passive self-locking function"), the literature report proposed a bidirectional motion MEMS driver based on the inchworm structure, and its driving mechanism uses two The tightening device is used as a locking structure, and the displacement change of the thermally expanded push rod is converted into the displacement change of the optical fiber embedded in it. Although the resolution is high, the actual displacement of the driver is very small (only about 4 μm), and the device is mainly for optical fiber adjustment research. , it is not suitable for some specific occasions, and the drive response speed is very slow, the drive mechanism and process are more complicated, and it is not suitable for micro-relays with two-way contact

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