Compliant electrodes based on platinum salt reduction in a urethane matrix

An elastomeric but electrically conducting material is presented that is fabricated using a method inspired by ionic polymer?metal composites. The Young's modulus is only 10?MPa, and yet the conductivity is nearly 1?S?cm?1 and the material remains electrically conductive under uniaxial strains of 30%. Furthermore, this electrode material is photopatternable. Fabrication begins with mixing the platinum salt tetraammineplatinum(II) chloride into a UV-curable acrylated urethane elastomer precursor (Loctite 3108). The mixture is crosslinked under UV light in less than a minute and can therefore be patterned if it is exposed through a mask. The salt is then chemically reduced with sodium borohydride, which results in the formation of 100?nm sized platinum nodules on the surface of the film.