Planar Magnetostrictive Micromechanical Actuator

A magnetostrictive actuator approach based on micromechanical structures is presented. Planar geometries are designed, comprising V-shaped beams and lever transmissions. Several V-shaped beams are stacked in parallel and two of such stacks are placed facing each other. Both are connected to a lever beam. When a magnetic field is applied, the magnetostriction of the active material leads to an elongation/shortening of the V-shaped beams. The lever transmission converts the magnetically induced elastic energy into a reliable in-plane displacement. The overall dimensions of the devices are in the range of 4 mm × 2 mm × 0.4 mm and hence, way smaller compared with state-of-the-art magnetostrictive actuators. For a magnetic flux density of 14 mT, a stroke displacement of 10.2 μm was achieved. With a spring stiffness of 5.56 N/m obtained from simulations, a theoretical area specific work of 72 μJ/m² was accomplished.