Inkjet-Printed Carbon Nanotube Electrodes with Low Sheet Resistance for Electrochemical Sensor Applications

A water-based carbon nanotube ink for inkjet printing was prepared by dispersing single-walled carbon nanotubes (SWCNT) with sodium n-dodecyl sulfate (SDS), an anionic surfactant. A standard Hewlett-Packard (HP) inkjet printer was employed to deposit the carbon nanotube ink onto a transparency film in order to form conductive electrodes. A sheet resistance as low as 132 Ω/□ was obtained for the carbon nanotube electrodes, which is one of the lowest values ever reported. Using inkjet-printed carbon nanotubes and screen-printed silver epoxy, a cheap, flexible, and disposable electrochemical sensor was fabricated and characterized using cyclic voltammetry (CV). The results of these tests indicate that the fully printed device behaves as a reliable electrochemical ionic sensor. Furthermore, the demonstrations presented in this work show that inkjet-printed carbon nanotube electrodes are very promising and have potential for use in many different applications.