Super-elastic liquid-metal-based triboelectric fibers and textiles

Flexible and wearable fiber-based triboelectric nanogenerators (FTENGs) have gained much attention in the wearable field due to their ability to convert waste mechanical energy from human motion into electrical energy. However, due to the limitation of preparation technology, FTENG still has the problems of poor flexibility and low electrical output performance. Herein, we prepared super-elastic microstructure triboelectric fibers (SMTFs) by using an extrusion combined with the thermal drawing process. The thermoplastic elastomer was drawn as the cladding, and filled with liquid metal EGaIn as the conductive electrode. The SMTFs show a superior stretchability (1900 % strain), and excellent conductivity. Utilizing a 5 cm long fiber to contact with PMMA medium, the average open circuit voltage was up to 10 V. Moreover, the SMTFs have a stable electrical output performance over 2000 s. The SMTFs were further woven into 8×8 cm² textiles for energy harvesting. The maximum electrical outputs were 150 V, 10 μA, and 33 nC, respectively. Our results indicate that the SMTFs fabricated by extrusion method combined with the thermal drawing process have the potential in wearable energy devices, intelligent textiles, and human-machine interaction.