Fabrication of ionic polymer metal composite actuator with palladium electrodes and evaluation of its bending response

We built up the way of fabricating ionic polymer metal composite (IPMC) actuator with palladium electrodes and evaluated the bending response under various solvents. We fabricated IPMC consisting of a thin Nafion® membrane, which is the film with fluorocarbon back-bones and mobile cations, sandwiched between two thin palladium plates. The surface resistivity was 2.88±0.18Ω/sq. , so it could be said to have enough conductive property. Then, we observed its cross section by using FE-SEM. As a result, palladium plates were evenly coated and its thickness was about 30μm. Then, we evaluated the bending response under the various solvents. In the evaluation, we study the influence to bending response by cation forms and mol concentration. We used Li⁺, Na⁺ and NH₄ ⁺ as cation form and all of them were 1.0mol/1. In terms of ionic radius, Li⁺, Na⁺, NH₄⁺. As mol concentration, we use 0.1mol/1, 0.5mol/1, 1.0 mol/1 and all of them were Na ⁺ form. As a result the bigger the ionic radius become, the larger bending response IPMC actuator showed, and the higher the ionic concentration become, the larger bending response IPMC actuator showed. Then, we conducted the modeling of IPMC actuator.