Super-elastic microstructured triboelectric fibers and textiles fabricated by extrusion and thermal drawing for smart-home applications

Flexible and wearable textile-based triboelectric nanogenerators (TENGs) have attracted extensive attention in wearable electronics owing to their ability to convert waste mechanical energy from human motion into electrical energy. However, the performances of TENGs are lower than those of planar/film configurations due to the complex fiber fabrications and limited mechanical freedom. In this work, we demonstrate an extrusion method combined with thermal drawing (ETD method) for continuous and scalable triboelectric fiber fabrication, providing longitudinal uniform fibers for hundreds of kilometers. Based on the ETD method, super-elastic microstructured triboelectric fibers (SMTFs) were fabricated, consisting of hollow elastomeric and liquid metal cores (EGaIn). The SMTFs showed excellent superelasticity with clear and uniform microstructures. The fibers could withstand strain up to 1800% and exhibited excellent electrical output performance. Utilizing a single fiber as the medium for triboelectric energy collection, the average open circuit voltage and instantaneous power density are respectively up to 210 V/m and 21 μW/m with a 40 MΩ external load resistance. The SMTFs could also be woven into deformable textiles with high electrical outputs up to 160 V, 10 μA, and 50 nC. In addition, the SMTFs-based textiles were further demonstrated as completely soft and stretchable components for self-powered sensing in smart home applications.