Magnetic Microactuators with Polysilicon Flexures

A novel microactuator technology that combines magnetic thin films with polysilicon flexural structures is described. Micromechanical structures, actuated by an off-chip magnetic field, are constructed in a batch-fabrication process that combines electroplatingwith conventional lithography, materials, and equipment. A microactuator consisting of a 400x(47-40)x7μm^3 rectangular plate of NiFe attached to a 400x(0.9-1.4)x2.25μm^3 polysilicon beam has been displaced by 1.2 mm, rotated by 180°, and actuated with ~0.2 nNmof torque. Theoretical expressions for the displacement and torque are developed andcompared to experimental results. This new microactuation technology has potentialapplications to micromanipulators, microgrippers, magnetometers and microphotonic systems.