Highly Stretchable, Conductive and Long‐Term Stable PEDOT:PSS Fibers with Surface Arrays for Wearable Sensors

Substantial progress has been made in exploring the novel structures and sensing mechanisms for wearable sensors, where high sensitivity plays an essential role. For fiber-based wearable sensors, the sensitivity mainly depends on the electroconductivity and surface microstructure of fibers. However, preparing highly conductive fibers along with excellent stretchability and long-term stability via facile and effective approaches is still challenging. Therefore, in this work, wet-spun poly (3, 4–ethylenedioxythiophene):poly (styrene sulfonate) (PEDOT:PSS) fibers with a superior conductivity of 105 S cm−1 and exceptional stretchability of 132% have been successfully achieved by adding urea and soluble copper salts into a coagulation bath. With the additional copper ions, the formation of a copper complex with fluff-like arrays morphology occurs spontaneously on the surface of fibers, while the existence of urea not only enhances their electroconductivity and stretchability, but also endows both with long-term stability. Meanwhile, the obtained fibers reveal fast response time and ultra-low detection limit to the external stimuli, and braided fabrics decorated with such fibers own potential applications for wearable electronic textiles. More importantly, this work explores the significance of durability for PEDOT:PSS fiber-based devices, inspiring a unique path for novel fiber design.