Development of Titanium Needle Probes for Neural Recording and Evaluation of Magnetic Resonance Imaging Artifacts

The aim of this research is to develop a mechanically flexible and strong neural probe with microelectrode array for future clinical applications in neural prosthetics and neurological disorder fields. This research specifically focuses on the development of neural recording electrodes with iridium oxide $(IrOx)$ electrodes on a titanium needle probe and discusses the fabrication techniques and their evaluation for physical properties and electrochemical performance. Microfabrication processes, such as inductive coupled plasma etching, were used to deeply etch the Ti needle structures on titanium foils, and microelectrode arrays with iridium oxide films were formed by electrochemical deposition for low impedance neural recording. Mechanical and electrochemical analyses were performed to verify the viability of Ti needle probes in vitro. The final section of this paper addresses the issue of magnetic resonance imaging artifacts of titanium needle probes, and test results are compared with similarly fabricated Si needle probes. The advantages of using a titanium needle probe are discussed in the application of neural probe electrodes, as well.