Amorphous and crystalline IrO₂ thin films as potential stimulation electrode coatings
By Thanawala, Sachin S.; Baird, Ronald J.; Georgiev, Daniel G. & Auner, Gregory W.
Published in Applied Surface Science
2008
Abstract
Amorphous and crystalline iridium oxide thin films with potential use as coating materials for stimulation electrodes were studied. Characterization of these films by cyclic voltammetry and impedance spectroscopy has revealed a considerable decrease in impedance and an increase in charge capacity of iridium oxide thin films after an electrochemical activation process in 0.9% NaCl solution. The surface morphology of these films was studied by scanning electron microscopy. The two types of IrO₂ films were also compared under conditions relevant to applications as stimulation electrodes. The results indicate that amorphous IrO₂ films have significantly higher charge storage capacity and lower impedance than crystalline IrO₂ films. This makes the amorphous films a preferable coating material for stimulation applications.