Self- Assembly and Magnetic Actuation of Three Dimensional Micro Hinged Mechanisms

Abstract

This paper describes three-dimensional (3D) micro structures fabricated using a simple self-assembly process involving the thermal shrinkage of polyimide. The proposed method enables hinged structures automatically to be rotated out of the wafer plane and to remain bent without the need to use any interlocking mechanisms. The hinged structures were fabricated using surface micromachining techniques involving heating in a furnace. An increase in the bending angle due to the shrinkage of polyimide was observed with increasing heating time, heating temperature, and length of the polyimide hinge. Of these three parameters, the heating time was found to be the most suitable for control of the bending angle. Microcubes were fabricated by this method and the self-assembly process was successfully visualized using a CCD camera. Furthermore, the hinged structures were actuated in external magnetic field after the self-assembly.