Activated iridium oxide films fabricated by asymmetric pulses for electrical neural microstimulation and recording

An efficient and reliable electrochemical method for preparation of activated iridium oxide films (AIROFs) microelectrodes by applying an asymmetric pulse train in Na2HPO4 solution was reported. The AIROFs microelectrodes exhibited a very high safe charge injection (Qinj) limit (∼4.1 mC/cm2), as well as excellent mechanical and electrochemical stability. Electrode impedance at 1 kHz has been significantly reduced by ∼92%. All of these characteristics are greatly desired for electrical neural microstimulation and recording applications. In addition, the activation method can be easily incorporated into other fabrication processes such as micro electrical mechanical system (MEMS).