A cost-effective fabrication of iridium oxide films as biocompatible electrostimulation electrodes for neural interface applications

Electrostimulation medical devices for neural diseases require electroactive and biocompatible interface materials to transmit signals from electrodes to targeting tissues. Iridium oxide is an attractive ceramic material for neurostimulation electrodes due to its desirable stability and biocompatibility. In this study, we developed a cost effective and thickness controllable process to fabricate iridium oxide film by chemical bath deposition (CIROF). Surface morphology, crystallinity, roughness, hydrophilicity, and charge storage capacity as well as biocompatibility of the CIROFs with different thicknesses were analyzed. Accordingly, the CIROFs present rough and hydrophilic surfaces for cell attachment and good biocompatibility for cell viability. In addition, the charge storage capacity (CSC) of the as-deposited and the annealed CIROFs were 78.29 mC/cm2 and 71.76 mC/cm2, respectively. Consequently, these results show advantages that make the CIROF a promising neurostimulation electrode material for implantable medical devices in neural systems.