An Overview of Advances and Challenges in Developing Nanofiber Yarns for Wearable Technology

The rapid progress in science and technology has resulted in substantial growth in the nanotextiles market and holds promising potential for the future. There is important research on nanotextiles, focusing on advancing wearable technology and widening its end uses. Nanofiber-based yarns are the foundation of this endeavor due to their exceptional electrical, mechanical, thermal, and optical properties, size, and interface/surface effects. These characteristics make nanofiber yarns well-suited for diverse applications, such as energy devices, sensors, protective clothing, aerospace, automotive, and biomedical engineering. However, nanotextiles face limitations for practical applications in terms of stability, durability, mechanical strength, and particularly scalability. Successfully addressing these challenges is important for the effective use of nanotextiles. Electrospinning emerges as a versatile nanofiber fabrication process, where substantial effort has been made in the direction of nanofiber yarn fabrication by optimizing process conditions and modifying fiber collecting mechanisms. Although these innovations are aiming towards achieving stable nanofiber yarns, many challenges still remain. This review offers a comprehensive analysis of the modified electrospinning processes employed in laboratory setups for nanoyarn production and discusses critically the reasons behind its limitations. It presents an in-depth overview of the fundamental properties of nanoyarns/textiles and critically examines the formations of nanoyarns and their properties. Additionally, the review explores how material selection, nanofiber morphology, strength, and mechanical properties affect the efficiency, stability, and durability of nanofiber yarns. Furthermore, the review highlights the importance of post-processing and it recommends how optimizing material, process, and post-process conditions can facilitate the rapid development of wearable smart textile applications.