Stretchable Conductive Fibers of Ultra-high Tensile Strain and Stable Conductance Enabled by Worm-shape Graphene Microlayer

Stretchable electrical conductors have demonstrated promising potentials in a wide range of wearable electronic devices, the conductivity of most of reported stretchable conductive fibers will be changed if be stretched or strained. But however, stable conductance is essential for wearable and stretchable device, to ensure the performance of wearable devices is stable. Inspired by the peristaltic behavior of arthropods, we designed a graphene coating similar to the caterpillar structure on the PU fiber surface, enabled by coating the worm-shape graphene microlayer onto polyurethane filaments. Such worm-shape filaments can be stretched up to 1010% with wide reversible electro-response range (0<ε<815%), long-term durability (>4000 stretching/releasing cycles), good initial conductivity (σ0=124 S m-1) and high-quality factor (Q=11.26). Remarkably, the worm-shape filaments show distinctive strain-insensitive behavior (ΔR/R0<0.1) up to 220% strain. Furthermore, the filaments as electrical circuits of LED to track signals from robust human joint movements are also demonstrated for practical application. Such worm-shape filaments with distinctive strain-insensitive behavior provide a direct pathway for stretchy electronics.