Fabrication of oriented carbon nanotube–alginate microfibers using a microfluidic device

Abstract

With the progress of microelectronic devices, more attention has been paid to carbon nanotube (CNTs) because of their excellent mechanical and electrical properties. A microfluidic-based method for fabricating oriented CNT strain-sensitive fibers is proposed in this work. By manipulating CNTs, NaAlg and CaCl2 solutions in a three-coaxial laminar flow glass capillary device, CNTs can be arranged in an oriented manner and solidified into microfibers with a hydrogel shell through a chemical polymerization reaction. The diameter of the fiber could be controlled by the microfluidic device. Scanning electron microscopy and Raman spectroscopy show that the CNTs are perfectly aligned along the fiber axis under the influence of the viscous drag force of the fluid, and the electrical and mechanical properties of the CNT fibers are obviously strengthened. Experiments suggest that the devices based on the oriented CNT–alginate microfibers are able to achieve simple motion monitoring function. The proposed microfluidic method is simple, cost effective and can be applied to produce functional nanomaterial fibers for application in flexible devices.