Investigation of Interfacial Capacitance of Pt, Ti and TiN Coated Electrodes by Electrochemical Impedance Spectroscopy
2002 (English)In: Biomolecular Engineering, ISSN 1389-0344, E-ISSN 1878-559X, Vol. 19, no 2-6, 67-71 p.Article in journal (Refereed) Published
Electrochemical processes at the electrode-electrolyte (body fluid) interface are of ultimate importance for stimulating/sensing electrode function. A high electrode surface area is desirable for safe stimulation through double-layer charging and discharging. Pt and Pt-Ir alloys have been the most common electrode materials. The use of TiN coating as the surface layer on the electrode has found increasing interest because of its metal-like conductivity, excellent mechanical and chemical properties, and the fact that it can be deposited with a high surface area. In this work, electrochemical impedance spectroscopy (EIS), which is a sensitive and non-destructive technique and widely used for characterization of electrical properties of electrode-electrolyte interfaces, was applied to investigate pure Pt and Ti, and TiN coated electrodes exposed to a phosphate-buffered-saline (PBS) solution. Platinized Pt and Ti were also studied for comparison. The capacitance value of the electrodes in PBS was obtained through quantitative analysis of the EIS spectra. The results reveal that the capacitance of the TiN coated electrodes with a rough surface is several hundreds times higher than that of a smooth Pt surface. Platinization of Ti can also increase the capacitance to the same extent as platina. EIS has been shown to be a powerful technique for characterization of stimulating/sensing electrodes.
Place, publisher, year, edition, pages
2002. Vol. 19, no 2-6, 67-71 p.
Effective surface area, Electrochemical impedance spectroscopy, Interfacial capacitance, Platinization, Stimulating/sensing electrodes, TiN coating
IdentifiersURN: urn:nbn:se:kth:diva-5060DOI: 10.1016/S1389-0344(02)00013-8ISI: 000178266800007OAI: oai:DiVA.org:kth-5060DiVA: diva2:7743
QC 201009202005-04-252005-04-252010-09-20Bibliographically approved