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

Abstract

Microelectrode\narrays of carbon nanotube (CNT)/carbon composite\nposts with high aspect ratio and millimeter-length were fabricated\nusing carbon-nanotube-templated microfabrication with a sacrificial\n“hedge”. The high aspect ratio, mechanical robustness,\nand electrical conductivity of these electrodes make them a potential\ncandidate for next-generation neural interfacing. Electrochemical\nmeasurements were also demonstrated using an individual CNT post microelectrode\nwith a diameter of 25 μm and a length of 1 mm to perform cyclic\nvoltammetry on both methyl viologen and dopamine in a phosphate-buffered\nsaline solution. In addition to detection of the characteristic peaks,\nthe CNT post microelectrodes show a fast electrochemical response,\nwhich may be enabling for in vivo and/or in vitro measurements. The\nCNT post electrode fabrication process was also integrated with other\nmicrofabrication techniques, resulting in individually addressable\nelectrodes.