Micromachined magnetic actuators using electroplated Permalloy

Results on design, fabrication, and testing of silicon micromachined magnetic actuators are presented. Electroplated, low-stress Permalloy (Ni₈₀Fe₂₀) material is the medium for magnetic interaction and force generation. The Permalloy piece is supported by a structural plate, which consists of polycrystalline silicon thin film prepared by low-pressure chemical vapor deposition (LPCVD). Magnetic actuators supported both by cantilever beams and by torsional beams can provide large force (on the order of 100 μN) and large displacement (on the order of 100 μm). The vertical loading force of magnetic actuators under external bias has been experimentally determined. Applications of such actuators in magnetically assisted levitation and parallel assembly of three-dimensional structures are demonstrated