Intrinsically stretchable porous liquid–metal conductor for multifunctional electronics applications

Abstract

As intrinsically stretchable materials for flexible electronics construction, liquid metal (LM) based composite conductors face challenges to achieve a high conductivity with minimum resistance increase due to the large dimensional change and poor wettability under a large tensile strain. To address this issue, a super-stretchable eutectic gallium indium (EGaIn) foamed elastomer composite is prepared with the assistance of a sugar template and O₂ plasma treatment, and displays a marginal resistance change of only ∼31.3% under a large strain of 500% due to the reorientation and elongation of the conductive network. The EGaIn conductor exhibits superior properties of a high uptake of LM and conductivity enhancement from ∼2.38 × 10⁴ (0% strain) to ∼2.97 × 10⁵ S m⁻¹ (500% strain) due to the strong capillary force during stretching. This work is a significant step toward high-performance stretchable conductors, demonstrating great potential in multifunctional device development including self-powered nanogenerators, electromagnetic interface (EMI) shielding, and thermal regulators.