Sputtered iridium oxide films for neural stimulation electrodes
- 6 October 2008
- journal article
- research article
- Published by Wiley in Journal of Biomedical Materials Research Part B: Applied Biomaterials
- Vol. 89B (2), 353-361
- https://doi.org/10.1002/jbm.b.31223
Abstract
Sputtered iridium oxide films (SIROFs) deposited by DC reactive sputtering from an iridium metal target have been characterized in vitro for their potential as neural recording and stimulation electrodes. SIROFs were deposited over gold metallization on flexible multielectrode arrays fabricated on thin (15 μm) polyimide substrates. SIROF thickness and electrode areas of 200–1300 nm and 1960–125,600 μm2, respectively, were investigated. The charge‐injection capacities of the SIROFs were evaluated in an inorganic interstitial fluid model in response to charge‐balanced, cathodal‐first current pulses. Charge injection capacities were measured as a function of cathodal pulse width (0.2–1 ms) and potential bias in the interpulse period (0.0 to 0.7 V vs. Ag|AgCl). Depending on the pulse parameters and electrode area, charge‐injection capacities ranged from 1–9 mC/cm2, comparable with activated iridium oxide films (AIROFs) pulsed under similar conditions. Other parameters relevant to the use of SIROF on nerve electrodes, including the thickness dependence of impedance (0.05–105 Hz) and the current necessary to maintain a bias in the interpulse region were also determined. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009This publication has 33 references indexed in Scilit:
- Microelectrode Array for Chronic Deep-Brain Microstimulation and RecordingIEEE Transactions on Biomedical Engineering, 2006
- In Vitro Comparison of the Charge-Injection Limits of Activated Iridium Oxide (AIROF) and Platinum-Iridium MicroelectrodesIEEE Transactions on Biomedical Engineering, 2005
- Perceptual thresholds and electrode impedance in three retinal prosthesis subjectsIEEE Transactions on Neural Systems and Rehabilitation Engineering, 2005
- Design of a high-resolution optoelectronic retinal prosthesisJournal of Neural Engineering, 2005
- Electrical stimulation of excitable tissue: design of efficacious and safe protocolsJournal of Neuroscience Methods, 2005
- Methods and Perceptual Thresholds for Short-Term Electrical Stimulation of Human Retina with Microelectrode ArraysPublished by Association for Research in Vision and Ophthalmology (ARVO) ,2003
- Visual perception in a blind subject with a chronic microelectronic retinal prosthesisVision Research, 2003
- The Effects of Prolonged Intracortical Microstimulation on the Excitability of Pyramidal Tract Neurons in the CatAnnals of Biomedical Engineering, 2002
- Chronic microstimulation in the feline ventral cochlear nucleus: physiologic and histologic effectsHearing Research, 2000
- Activated Ir: An Electrode Suitable for Reversible Charge Injection in Saline SolutionJournal of the Electrochemical Society, 1983