Sculpting Liquid Metal Stabilized Interfaces: A Gateway for Liquid Electronics

Abstract

Liquid electronics foresee potential applications in soft-robotics, printed electronics, and healable electronics. The intrinsic shortcomings of the solid-state electronics can be offset by liquid conductors. Alloys of gallium have emerged as a transformative material for liquid electronics due to its intrinsic fluidity, conductivity, and low toxicity. However, sculpting liquid metal or its composite into 3D architecture is a challenging task. To tackle the issue, herein, we have explored the interfacial chemistry of metal ions and tannic acid (TA) complexation at liquid-liquid interface. First, we have established that MIII -TA network at liquid-liquid interface could structure liquid in liquid by jamming of the interfacial film. The surface coverage of the droplet largely depends on concentration of metal ions, oxidation state of metal ions and pH of the surrounding environment. Further extending the approach, we have demonstrated that TA functionalized gallium nanoparticles (Ga NPs) are also able to sculpt the liquid droplets in the presence of transition metal ions. Finally, a mold-based free-standing 3D architecture is obtained using the interfacial reaction and interfacial crowding of metal-phenolate network. The conductivity measurement reveals that these liquid constructs can be used for low-voltage electronic application, thus opening a doorway for liquid electronics.