Sputtered Iridium Oxide Coating of the Silicon Neural Probe as a Neural Interface for Single-Neuron Recording

High-precision neural electrodes at the level of a single neuron are essential for identifying the neural mechanisms underlying sensory, motor, and cognitive processes in the brain. Although microelectrodes can enhance spatial resolution, their smaller size can result in charge edge effects, which increase the impedance and reduce the charge storage capacity (CSC). In recent years, nanomaterials and surface engineering techniques have been employed to enhance electrode performance; however, shortcomings such as insufficient mechanical strength and a low CSC remain. Iridium oxide (IrOx) is an ideal choice due to its high CSC, low impedance, and stability. However, its optimal preparation and modulation of performance on microscale electrodes still require an in-depth study. This paper systematically investigates how the microelectrode structure, morphology, and electrochemical properties are affected by IrOx thin films prepared by magnetron sputtering under varying oxygen/argon flow rates. The aim is to reveal the relationship between process parameters and electrode performance and to provide theoretical and technological support for developing neural probes with highly sensitive single-neuron recording capability.