Silk inspired in-situ interlocked superelastic microfibers for permeable stretchable triboelectric nanogenerator

Abstract

Wearables and on-skin triboelectric nanogenerator (TENG) highly desire intrinsic stretchability, favorable permeability and waterproofness, fibers/textiles as one of the ideal substrates could meet the requirements. However, realizing the versatile integration of hydrophobic elastic fibers with electrodes remains a huge challenge. Herein, inspired by the sericin-bundled silk with outstanding stretchability, we develop a microfibers-membrane with omnidirectional superelasticity, permeability and superhydrophobicity (SPSM) by synchronous electrospinning of styrene-isoprene (SIS) block copolymers and electrospraying of the fluorinated SiO2 nanoparticles. Co-solvent welding effect free of extra binders is proposed for the generation of in-situ anchored junctions between the SIS fibers, as well as achieving the anchoring effect for enhanced integration of SIS fiber-membranes with a variety of conductors such as sputtered gold (Au) layer, vacuum filtrated liquid metal-silver nanowires (LM-AgNWs) network and printed liquid metal-silver flakes-SIS (LM-AgFKs-SIS) ink, creating diverse elastic conductors and triboelectric-active-materials with optional advantages in mechanical stability, electrical robustness, triboelectric output and permeability. A self-cleaning SPSM-based single-electrode stretchable TENG (STENG) is demonstrated adaptive for tapping, stretching, bending and humidity, realizing a breathable self-powered sensor for materials identifying and hand posture monitoring. This work proposes a versatile superelastic fiber material competent for permeable STENGs and wearables with environment adaptivity.