Wet‐Spun Core–Sheath Fibers for Smart Wearables

Abstract In recent years, substantial progress has been made in the development of novel flexible and conductive materials, driving the emergence of a wide range of electronic devices for smart wearable applications. Among them, core‐sheath composite fibers—integrating the benefits of both core and sheath layers—exhibit outstanding flexibility and electrical conductivity, making them ideal for such technologies. Among various fabrication methods, wet‐spinning has gained prominence due to its low energy consumption and cost‐efficiency. This review presents recent advances in wet‐spun core‐sheath fibers for smart wearables. By comparing three wet‐spinning techniques—conventional, microfluidic, and dry‐jet wet‐spinning—it highlights their key characteristics, including spinning mechanisms, fiber morphologies, and respective advantages and limitations. The influence of critical process parameters such as drawing ratio, coagulation bath conditions, and spinning speed on fiber structure, mechanical properties, and conductivity is systematically analyzed. Commonly used materials and their performance in fiber fabrication are also discussed, alongside practical applications of these fibers in flexible sensors, nanogenerators, and supercapacitors. Finally, the review outlines future challenges in integrating wet‐spun core‐sheath fibers into flexible electronic textiles, providing direction for ongoing research and innovation.