Flexible Neural Electrode Array with Vertically Aligned Carbon Nanotubes Microstructure for High Sensitivity Measurement of Neurochemicals

Abstract

This paper reports a flexible microelectrode array based on microstructures with vertically aligned carbon nanotubes (VACNTs) and presents the monitoring of neurochemical signals. VACNTs have high electrical conductivity and chemical stability along with their high-density structure. The unique pyramid-shaped microstructure with VACNTs is implemented into the electrode. The 32-channel microelectrode is fabricated through microfabrication, enabling batch process. VACNT dramatically lowered the impedance of the electrode to 17.6 kΩ, which is 93% lower than the impedance of a Pt electrode. The VACNT electrode also achieved a high charge storage capacity (CSC) of over 1000 mC∙cm-2, which allows for high-sensitivity measurement of neurochemicals. The electrode shows high sensitivity of sensing hydrogen peroxide (H2O2) and glucose with sensitivity over 200 times higher than the Pt electrode, validating the capability of neurochemical monitoring. In conclusion, we have demonstrated the superior performance of our VACNT-based flexible microelectrode array, showcasing its potential for diverse applications in studying brain functionalities and etiologies of neurochemical-associated brain disorders.