Scalable Manufacturing of Flexible Graphene Fiber for Wiring and Electronics

B. Shen, W. Shou
University of Arkansas,
United States

Keywords: lightweight fibers, scalable graphene coating, conformal fiber application

Summary:

With the era of the Internet of Things (IoT) and the pervasive electrification needs of almost everything, such as vehicles, lightweight and flexible conductors beyond traditional copper are becoming indispensable. It is known that ideal graphene conductivity is in the order of 108 S/m, which is higher than the typical copper conductivity of 5.8×106 S/m; meanwhile, the density of graphene is only about 25% of copper. Therefore, making conductive graphene fiber can potentially impact our society with various electrical applications. However, by now scalable manufacturing of high-conductive graphene fiber remains challenging. Recently work reported various coating approaches to attach graphene or graphene oxides (GO) on fibers and yarns, yet, the alignment and stacking of graphene and GO flakes are random, which deteriorates the conductivity. Furthermore, the bonding between the core fiber and the coated graphene is not mechanically robust. Here, we leverage a low-cost, scalable drawing technique to continuously fabricate microfiber, which is subsequently fed through a customized coating device to realize robust graphene coating. Different manufacturing parameters are optimized to obtain a reliable and high-quality coating. In order to realize a conformal coating of graphene flakes with strong bonding, different materials, including polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), polyether ether ketone (PEEK), and polyacrylonitrile (PAN) are investigated and compared. Meanwhile, different fiber diameters are studied to understand the influence of curvature on the conformal coating. Our manufacturing technique and analysis are expected to promote the research as well as the adoption of graphene fibers in practical applications.