Chemical vapour deposited carbon nanotube coated microelectrodes for intracortical neural recording

Implantable electrodes are one of the most common tools in electrophysiology research, both for acute recording of intracortical signals and for chronical experiments. A stable low-impedance electrode to tissue interface is fundamental to obtain reliable, long term recordings of the central nervous system activity. Commonly used metal electrodes do not fully meet such requirements, as their surface often degrades in time and they have high impedance. Nanostructured coatings, such as platinum black in the past and more recently conductive polymers, have been largely investigated as means to improve the electrodes for in vivo recording. With the same purpose, carbon nanotubes (CNTs) composite coatings have been obtained by chemical and electrochemical methods. In the present work we have used reference commercial microelectrodes for in vivo intracortical recording made from quartz insulated platinum/tungsten wires, mechanically ground, as a substrate to directly grow CNTs in situ by chemical vapour deposition. The analysis of the electrochemical and morphological properties of the obtained CNT coatings is presented and discussed. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim