Modification of a Substrate Roughness for a Fabrication of Freestanding Electroplated Metallic Microstructures

This study aims to demonstrate a simple fabrication technique of freestanding electroplated metallic microstructures by modifying a substrate roughness. The proposed technique utilizes counter effects between two forces, i.e. an intrinsic force causing shrinkage in an electroplated metallic microstructure, and an adhesive force adhering a metallic microstructure to a substrate. With the modification of substrate roughness until the adhesive force becomes weaker than the induced intrinsic force, electroplated metallic microstructures would spontaneously release from the substrate after the electroplating process. Three parameters, i.e. substrate roughness, electroplated square structure’s area and electroplated rectangular structure’s width-to-length ratio, were experimentally studied. The results showed that the electroplated structure with a smaller size and smaller width-to-length ratio was more easily detached from the substrate for a given substrate roughness. In addition, for the same electroplated structure, a substrate with less roughness allowed a detachment of electroplated microstructure more easily.