High-Yield Assembly of Hinged 3-D Optical MEMS Devices Using Magnetic Actuation

We have developed a new magnetic actuation process for hinged, surface micromachined structures to assemble threedimensional optical devices with high efficiency and high yield. Electroplated magnetic material (Permalloy) is integrated with two types of hinged microstructures and the magnetic actuation process has been experimentally characterized. Under a given external magnetic field, the angular displacement of a hinged structure is determined by the volume of the magnetic material or by the stiffness of an auxiliary flexural loading spring. Preliminary design rules for achieving asynchronous actuation of hinged microstructures have been established to enable effective parallel assembly of three-dimensional devices. We have demonstrated parallel actuation of arrays of individual microstructures and three-dimensional assemblies under a globally applied external magnetic field.