Electrochemically Directed Assembly of Carbon Nanotubes (CNTs) and Collagen Macromolecules into Macroscopic Hybrid Fibers

Other than spinning from aligned Carbon Nanotube (CNT) arrays into free-standing yarns or co-spinning with a polymer solution, there is a lack of approach to assemble individual CNTs into anisotropic macroscopic fibers. Here we report that highly ordered and anisotropic collagen-CNT macroscopic fibers have been prepared through directed assembly by an electrochemical process. This fabrication method is based on assembly of CNTs along with collagen to attain hierarchical alignment properties that are difficult to achieve through conventional methods. Due to high loading of CNTs, the formed hybrid collagen-CNT fiber is electric conductive in the dry state. Polarized Raman analysis confirmed the high degree of CNT alignment in the fibers. Mechanical tensile testing showed that mechanical properties of hybrid collagen-CNT fibers are superior to counterpart neat collagen fibers. These biocompatible hybrid CNT-collagen fibers prepared by this method have great potential for various biomedical applications (e.g., neural interface, tendon/ligament repair, sutures, etc.)