A flexible bioelectrode based on IrO2–coated metallized polypropylene micromembrane

Abstract We demonstrate the fabrication of a flexible and conductive bioelectrode via the electrodeposition of IrO2 nanoparticles on a metalized polypropylene micromembrane (PPMM). The metalized PPMM is prepared by carrying out conformal electroless deposition of Au on individual polypropylene (PP) fibers of PPMM using both polydopamine and polyvinyl alcohol as the surface–modifying agents to improve the hydrophilicity of PPMM. Images from scanning and transmission electron microscopes, as well as analysis from energy dispersive X–ray spectrometer and X–ray photoelectron spectroscopy confirm the successful formation of IrO2 nanoparticles on individual PP fibers of metalized PPMM. For bio–stimulating purpose, the IrO2–coated PPMM reveals an impressive charge–storage–capacity of 54.6 mC/cm2 in cyclic voltammetry, In addition, under a symmetric bi–phasic current pulse, its charge–injection–capacity reaches 466 μC/cm2. Since the entire constituents for the IrO2–coated PPMM are bio−compatible, we envision its potential use as a bioelectrode in implantable biomedical devices.