Highly integrated, scalable manufacturing and stretchable conductive core/shell fibers for strain sensing and self-powered smart textiles

Although the research in triboelectric nanogenerator (TENG) textiles has seen a rapid development recently, their integrated and mass fabrication process is still challenging, which hinders its further applications for wearable sensors. Herein, highly integrated and scalable manufacturing conductive composite fibers for weaving TENGs are presented, which might overcome the major problems. The fibers possess liquid alloy/silicone rubber core/shell structures made by simultaneously injecting liquid alloy and silicone rubber into the separate input ports of a coaxial needle, followed by automatically assembled from the output. The liquid alloy/silicone rubber core/shell fiber (LCF) has both good pliability and high resistance-strain sensitivity, which is beneficial for serving as strain sensors directly, and for incorporating with woven for textile-TENGs (t-TENGs)-based self-powered sensoring application. As a result, the open-circuit voltage (V_oc), short-circuit current (I_sc), short-circuit transferred charge (Q_sc) and maximum power density of 4 × 4 cm² t-TENG are 175 V, 15 μA, 66 nC and 469 mW/m², respectively. Additionally, the t-TENG is mechanically robust, chemically stable and easy-cleaning for daily use. The wearable t-TENG devices can be used to detect human motions. This work provides a novel method of scalable manufacturing LCFs for weaving wearable t-TENGs, contributing to the development of t-TENGs and wearable self-powered sensors.