Self-supporting carbon nanotube films as flexible neural interfaces

Advances in neural interface technologies have sought to identify electroactive materials that are able to translate neural depolarisation events into digital signals or modulate neural firing through ionic or electrical stimulation with greater efficiency. An ideal material for neural recording and/or stimulation should possess low electrical impedance coupled with a high cathodic charge storage capacity (CSCC), charge injection capacity (CIC) and electroactive surface area (ESA), as well as optimal mechanical biomimicry. In this study, we present the robustness of self-supporting CNT films as neural interfaces, combining advantageous electrical and mechanical properties with high cytocompatibility. Films were observed to possess a high CSCC (29.95 +/- 0.91 mC cm(-2)), CIC (352 +/- 5 mu CV-1 cm(-2)) and ESA (0.908 +/- 0.053 cm(2)), low impedance (110 Omega at 1 kHz), low resistance (75 +/- 13 Omega) and high capacitance (378 +/- 9 mu F cm(-2)), and outperformed Pt control electrodes. Self-supporting CNT films were also found to facilitate neuron growth and decrease the presence of reactive astrocytes in a mixed neural cell population. Self-standing CNT films were shown to be promising materials for the design of flexible and cytocompatible neural interfaces. (C) 2018 Elsevier Ltd. All rights reserved.This publication has emanated from research conducted with the financial support of Science Foundation Ireland (SFI) and is co-funded under the European Regional Development Fund under Grant Number 13/RC/2073 and SFI Technology Innovation Development Programme, grant no. 15/TIDA/2992. This project has received funding from National Science Center, Poland (under the Polonez program, grant agreement UMO-2015/19/P/ST5/03799) and the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreements No. 713690 and 665778. The authors acknowledge the facilities and scientific and technical assistance of the Center for Microscopy & Imaging at the National University of Ireland Galway, a facility that is funded by NUIG and the Irish Government's Programme for Research in Third Level Institutions, Cycles 4 and 5, National Development Plan 2007–2013. D.J. and K.K. would also like to acknowledge the Ministry for Science and Higher Education for the scholarship for outstanding young scientists (0388/E-367/STYP/12/2017 and 649/STYP/12/2017, respectively).peer-reviewed2020-10-2