Visualization of ion transport in Nafion using electrochemical strain microscopyElectronic supplementary information (ESI) available: Details of ESM image in ambient and water conditions. See DOI: 10.1039/c5cc07412f

The electromechanical response of a Nafion membrane immersed in water was probed using electrochemical strain microscopy (ESM) to redistribute protons and measure the resulting local strain that is caused by the movement of protons. We also measured the relaxation of protons from the surface resulting from proton diffusion. Using this technique, we can visualize and analyze the local strain change resulting from the redistribution and relaxation of hydrated protons. The local strain change resulting from the proton redistribution and relaxation in Nafion could be visualized using electrochemical strain microscopy.