Microfabricated actuator with moving permanent magnet

A microactuator is presented which uses electromagnetic force generation within micromachined silicon devices. A rare-earth permanent magnet is bonded on a movable micromachined silicon plate suspended by thin silicon beams. A monolithically integrated planar coil is used to generate a magnetic field which forces the magnet to move vertically. Using a magnet with a dimension of 1.5×1.5×1.0 mm³ and a 17-turn coil driven with 300 mA, a static elevation of 70 μm has been achieved. The actuator concept offers a variety of application-specific design possibilities. The use of a moving permanent magnet allows a magnetic coupling of the actuator force to the environment. By integrating a magnetic field sensor and signal processing, an active, controlled microsystem can be realized. High, long-range forces can be generated in order to realize devices with large deflections