Electrophysiological Recording With Activated Iridium Oxide: Effective Electrode Area, Not Total Impedance, Determines Performance.

Abstract

Platinum electrodes are used in many bionic devices; however, they have limited charge injection capacity (CIC) and signal-to-noise ratio (SNR), restricting performance. Iridium oxide has substantially larger CIC and reduced impedance compared to platinum. While these types of electrochemical measurements are typically used to infer improved electrophysiological performance, there are no studies demonstrating this correlation. This article compares the electrochemical and acute electrophysiological recording performance of iridium and electrochemically activated IrOx. Increased iridium activation reduced total impedance at low-intermediate frequencies and steady-state electroactive area but ..