Microfabrication of Heterogeneous, Optimized Compliant Mechanisms

Metal deposition by electroplating has been extensively used and analyzed for industrial applications, but it remains insufficiently characterized for fabricating compliant micromechanisms. This research presents a new fabrication process for heterogeneous optimized compliant mechanisms that consists of placing two materials side by side as opposed to the convention of stacking materials layer by layer. The fabrication process uses standard bulk micromachining and electroplating techniques. This paper reviews and discusses the theory and method of electroplating for obtaining optimum structural and surface morphology. We also present a novel method for protecting a silicon wafer from wet etching using black wax. In fabricating these two-material mechanisms, we found that optimum microstructures can be obtained by electroplating at a low-current density while maximizing the reaction kinetics.