Fabrication of High Aspect Ratio Millimeter-Tall Free-Standing Carbon Nanotube-Based Microelectrode Arrays

ACS Biomater Sci Eng. 2018 May 14;4(5):1900-1907. doi: 10.1021/acsbiomaterials.8b00038. Epub 2018 Apr 9.

Abstract

Microelectrode arrays of carbon nanotube (CNT)/carbon composite posts with high aspect ratio and millimeter-length were fabricated using carbon-nanotube-templated microfabrication with a sacrificial "hedge". The high aspect ratio, mechanical robustness, and electrical conductivity of these electrodes make them a potential candidate for next-generation neural interfacing. Electrochemical measurements were also demonstrated using an individual CNT post microelectrode with a diameter of 25 μm and a length of 1 mm to perform cyclic voltammetry on both methyl viologen and dopamine in a phosphate-buffered saline solution. In addition to detection of the characteristic peaks, the CNT post microelectrodes show a fast electrochemical response, which may be enabling for in vivo and/or in vitro measurements. The CNT post electrode fabrication process was also integrated with other microfabrication techniques, resulting in individually addressable electrodes.

Keywords: carbon nanotube; cyclic voltammetry; electrical resistivity; microelectrode array; neural probe.