Current frontiers in graphene fiber technology and applications

Graphene fibers (GFs) have emerged as a transformative class of materials that bridge the exceptional intrinsic properties of two-dimensional graphene with scalable macroscopic architectures suitable for practical applications. This review highlights the evolution of graphene fiber development, beginning with a detailed exploration of their diverse morphologies, including cylindrical, porous, belt-type, hollow, helical, elastic, and core–sheath structures, which are intricately linked to their performance across various domains. It further examines a wide range of fabrication techniques such as wet spinning, dry spinning, plasticization spinning, high-speed blow spinning, dry-jet wet spinning, chemical vapor deposition, and dry film scrolling, emphasizing how processing strategies directly influence fiber alignment, stacking density, and defect generation, ultimately determining the mechanical and electrical properties of the fibers. Notably, recent innovations have enabled the production of GFs with tensile strengths exceeding 3 GPa and electrical conductivities surpassing 106 S/m, which has been made possible through improved crystallinity, sheet orientation, and interfacial control. The review also presents cutting-edge applications of graphene fibers, showcasing their versatility in neural recording microelectrodes, regenerative dentistry, wearable textiles, and multifunctional sensors, where their unique combination of high conductivity, flexibility, and biocompatibility offers significant advantages. While substantial progress has been made, critical challenges remain to unlock their true potential, particularly in minimizing structural defects, achieving uniform large-area graphene alignment, and fabricating pristine graphene fibers that are free of any binder. The review concludes with a forward-looking perspective, identifying key research directions and innovations needed to overcome these hurdles and fully realize the role of graphene fibers as next-generation materials in flexible electronics, biomedical systems, and advanced structural applications.