Spinning, Functionalizing, and Assembling of Flexible Fiber Electronics and Their Applications

Distinguished by their flexibility, lightweight, and tunable functionalities, fibers have become a pivotal research focus in flexible electronics, wearable technologies, soft robotics, etc. Working either individually or in assembled forms, fibers offer versatile roles in providing mechanical and spatial support for active materials, conductive interconnects, and miniaturized components, which further expands their applicability. Obtaining the desired fiber electronics requires elaborate steps, including fabricating conductive fibers using advanced spinning techniques, functionalizing them into fiber devices, and assembling them for specific applications. This review analyzes the recent progress in fiber spinning, functionalization, and assembly technologies. Key fabrication parameters will be discussed, aiming to provide roadmaps to master the techniques for controllably distributing conductive and functional materials on fiber substrates, achieving fiber electrodes and devices with tailored conductivity, mechanical robustness, and functionalities. Next, the potential spinnable and functional materials that underpin the development of high-performance fiber devices will be discussed, highlighting the structure-property correlations. Furthermore, the practical applications of functional fibers in energy storage and conversion, as well as wearable sensors, will be elaborated. Lastly, an in-depth discussion on the current challenges and future opportunities in this field of research will be presented, with the hope of guiding future research.