Strong and Highly Conductive Carbon Nanotube Fibers as Conducting Wires for Wearable Electronics

Carbon nanotube (CNT) fibers (CNTFs) have potential for use as conducting wires in wearable electronics, but this application requires significant improvement in the mechanical and electrical properties of CNTFs. This work describes the correlation between the synthesis conditions and the properties of CNTFs according to the configuration of the injection tube during the direct spinning process. Adjusting the configuration of the injection tube is highly effective in improving the synthesis of CNTFs because the gas flow pattern critically affects the synthesis. CNTFs synthesized from reactants injected into the high-temperature region of the reactor are composed of CNTs with a uniform diameter and have a denser internal structure than CNTFs synthesized from reactants injected into the low-temperature region. As-spun CNTFs with a specific strength of up to 2.29 N/tex (average: 2.03 N/tex) were synthesized by directly injecting the reactants into the high-temperature region using a long injection tube. This study increases the understanding of how synthesis conditions affect the specific strength of as-spun CNTFs and demonstrates the significance of properly designing the reactor configurations.