Eutectic Gallium-Indium metal alloy (EGaIn) is a non-toxic liquid at room temperature with a unique combination of rheological, thermal, and electrical properties that makes it attractive for applications in soft electronics, catalysis, 4 energy storage plasmonics, 2D-materials synthesis, and molecular electronics. In the presence of oxygen, a selfpassivating 0.7-2 nm thick gallium oxide layer forms spontaneously at the exposed interface, endowing EGaIn with non-Newtonian rheological properties; as a result, liquid EGaIn can be molded into various geometries (e.g., micro-/nano-sized spheres, rods, and cones, or injected into microchannels ).