Development in combined Si-based magnetic microactuator

We present a new silicon based thin film magnetic actuator could be used as an acoustical transducer. Different from the previously presented magnetic actuators the manufactured actuator in this work combines for the first time the electromagnetic and the magnetostrictive effect. The new and cost-effective design consists basically of a FeCo thin film deposit on micro mechanically processed silicon oxide substrate and leads to static deflection above 300mum at a magnetic field of 100mT. Two coils are also integrated in the fabrication process to generate magnetic driving fields in different orientations. To confirm the merits of the actuator, its properties are compared to ones with non magnetostrictive NiFe film. It is also shown that the use of a metallic underlayer slightly improve the Bending. For acoustic applications the implementation of a special multilayer design and the variation of the residual stress in the actuator by the use of doped substrate increase his performance