Stretchable Conductive Fibers of Ultrahigh Tensile Strain and Stable Conductance Enabled by a Worm-Shaped Graphene Microlayer.

Stretchable electrical conductors have demonstrated promising potentials in a wide range of wearable electronic devices, but the conductivity of most reported stretchable conductive fibers will be changed if be stretched or strained. Stable conductance is essential for wearable and stretchable devices, to ensure the performance is stable. Inspired by the peristaltic behavior of arthropods, we designed a graphene coating similar to the caterpillar structure on the polyurethane (PU) fiber surface, enabled by coating the worm-shaped graphene microlayer onto polyurethane filaments. Such worm-shaped filaments can be stretched up to 1010% with a wide reversible electroresponse 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-shaped filaments show distinctive strain-insensitive behavior (ΔR/R0 < 0.1) up to 220% strain. Furthermore, the filaments as electrical circuits of light emitting diodes (LEDs) to track signals from robust human joint movements are also demonstrated for practical application. Such worm-shaped filaments with distinctive strain-insensitive behavior provide a direct pathway for stretchy electronics.