Self‐Healing Liquid Metal‐Elastomer Circuits for Robust Underwater Electronics

ABSTRACT Soft electronics for marine environments require circuit materials that are mechanically compliant and environmentally robust. Liquid metal (LM) composites are promising candidates for these systems due to their reconfigurable conductivity, stretchability, and electrical self‐healing. However, the stability of these unique electromechanical properties in underwater environments remains largely unknown. Here, we address this gap and demonstrate that essential electromechanical behaviors of LM‐elastomer composites, including the formation of electrically conductive networks, strain‐tolerant conductivity, and electrical self‐healing are preserved or even enhanced after 28 days of aging in ambient, freshwater, and saltwater conditions. To demonstrate this resilience, an LM–elastomer LED circuit is created which remains operational after saltwater exposure and continues to function and self‐heal under severe puncture damage and deformation. Electrical self‐healing is also maintained during continuous applied voltage in saltwater conditions. These results highlight the robustness of LM‐elastomer composites, establishing them as strong candidates for deformable, self‐healing soft electronics in harsh aquatic environments relevant to sensing, communication, and robotic systems.