Naturally Oxidized EGaIn/SiO2 Fabric Electrodes for Sustainable Wearable Electronics with High Conductivity and Strain-Insensitivity.

Abstract

The development of environmentally friendly stretchable electrodes that combine high conductivity with mechanical stability remains a critical challenge for sustainable wearable electronics. To address this, liquid metal eutectic gallium-indium (EGaIn) as the conductive material is utilized. While EGaIn offers excellent conductivity and fluidity, its poor wettability and high surface tension have limited practical applications. An innovative solution is developed by repurposing EGaIn's naturally forming oxide layer (Ga₂O₃) as an interfacial activator. This breakthrough allows us to create highly adhesive EGaIn/SiO₂ composite slurry without relying on synthetic surfactants. The resulting fabric electrodes achieve remarkable performance: conductivity reaches 3.18 × 10⁶ S m^-1 with minimal strain sensitivity (gauge factor, GF = 0.0092), maintaining stable function even at 50% tensile strain. After 2500 stretching cycles at 30% strain, the electrodes retain 93% of their initial resistance while withstanding bending, twisting, and stretching deformations. Notably, this stretchable fabric electrode based on natural oxides is successfully integrated into flexible circuits and applied to sign language recognition gloves, enabling stable signal transmission. The electrode replaces conventional surfactants with environmentally friendly materials, providing a sustainable solution for low-cost, high-performance wearable electronic devices.