Surface Roughness-Dependent Corrosion: Implications for Cochlear Implant Reliability

Abstract The corrosion behavior of platinum electrodes in cochlear implant (CI) systems is a critical factor affecting their long-term functionality. This study investigated the influence of the surface roughness of the platinum electrodes on their corrosion behavior. The results of in vitro experiments indicate that higher surface roughness tends to accelerate corrosion by providing numerous initiation sites. Although the electrochemical measurements of platinum electrodes with different surface roughnesses showed only slight differences in terms of shifts in potentials and higher corrosion current densities, data from the literature suggests an enhanced charge capacity with rougher surfaces. These findings contribute to an understanding of the failure mechanisms of CIs and can ultimately help to improve the design and durability of CI systems.