Microactuators with moving magnets for linear, torsional or multiaxial motion

Various types of actuators have been fabricated that make use of electromagnetic forces within micromachined silicon devices. An Nd-Fe-B permanent magnet is bonded to a movable silicon plate suspended by thin silicon beams. Planar coils arc integrated monolithically on the chip to gencrate the driving magnetic field. Using a thick photoresist, gold lines with a thickness of 26 Mym are electroplated. Different actuators for vertical, torsional and multiaxial motion have been investigated. Vertical and torsional deflections of the order of 100 Mym and 10 degree, respectively, have been obtained using a magnet with a typical dimension of 1 mm.