A Pt-Ir-W Ternary Alloy for Enhanced Electrochemical Performance and Mechanical Properties in Neural Microelectrode Applications

Abstract

Reducing the cross-sectional dimensions of microelectrodes has been demonstrated to decrease damage to nerve tissue and extend their operational lifetime. However, this may result in an elevated electrode impedance and a diminished signal-to-noise ratio. Moreover, a reduction in size will result in a decrease in the critical buckling force, thereby increasing the probability of bending during insertion. This study presents a novel platinum-iridium-tungsten (Pt-Ir-W) ternary alloy electrode material, designed to enhance the mechanical and electrochemical properties of microelectrodes. The addition of W inhibits dislocation motion and grain boundary migration, significantly improving the mechanical properties of the alloy. Additionally, it increases surface activity, which in turn enhances its electrochemical performance. The experimental results demonstrated that the Pt-Ir-W alloy significantly reduced the strain on the simulated brain tissue during insertion, thereby minimising trauma. The results of the electrochemical tests indicated that the alloy exhibited a reduction in impedance and an increase in charge storage capacity. Biocompatibility assessments have demonstrated that the alloy is non-toxic to PC12 cells and exhibits favourable haemocompatibility. These findings provide new insights into the optimisation of metallic materials for use in neural electrodes.