A Facile Fabrication and Transfer Method of Vertically Aligned Carbon Nanotubes on a Mo/Ni Bilayer for Wearable Energy Devices

Abstract

Carbon nanotubes are a promising material for flexible/wearable electrochemical device due to their mechanical softness, chemical stability, and high conductivity. Furthermore, the vertically aligned form of carbon nanotubes (VACNTs) have a large surface area due to their unique three-dimensional (3D) nanostructure. Thus, VACNTs are particularly useful for wearable electrochemical sensors and/or energy devices. However, VACNTs are generally grown via a high-temperature chemical vapor deposition process, which requires a rigid substrate. As a flexible/wearable device platform, therefore, VACNTs should be transferred from rigid substrates to soft substrates. Here, a facile fabrication and transfer method of a unique 3D nanostructure, that is, VACNTs on the Mo/Ni bilayer, for high performance flexible/wearable devices is reported. After growth of VACNTs on a Mo/Ni bilayer, VACNTs with the Mo/Ni bilayer can be easily peeled-off from the SiO2 wafer by using weak adhesion of Ni to SiO2 for transfer printing onto polymeric/elastomeric substrates. Moreover, the Mo layer helps facile growth of VACNTs, and the Mo/Ni bilayer underneath VACNTs maximizes the lateral current flow. The proposed 3D nanostructure (VACNTs on the Mo/Ni bilayer) is successfully applied as flexible electrodes for high-performance wearable asymmetric supercapacitors.