IPMC Actuators Fabricated Using MEMS Technology

Abstract

Fabrication of ionic polymer metal composite (IPMC) on Si substrate and micromachining of IPMC are basic technologies for developing MEMS devices using IPMC. Adhesion of IPMC with the substrate is essential to fabricate IPMC on the substrate. Swelling of IPMC with water makes IPMC peel from the substrate due to the internal stress. To enlarge adhesion force of IPMC with the Si substrate, we have fabricated IPMC on an anodic-oxidized porous Si surface, which dramatically increased adhesion area between the IPMC and the substrate. Fabricated IPMC didn't peel from the Si substrate during the operation in water. Photolithography is a key technology in MEMS fabrication. However, water and organic solvents used in the fabrication process also swell IPMC and lower machining accuracy. We have developed a machining technology of microminiaturized IPMC by mainly using dry processes: reactive ion etching of Nafion film through metal mask, and a selective electrode formation using a plasma irradiation on Nafion and an electroless gold plating. An array of IPMCs with a width of 100 μm was fabricated and their operations in water were confirmed.