Ga-based liquid metal has drawn attention in the field of interface science due to its large deformability. However, the spreading and shaping of liquid metal still remain a huge challenge to be solved owing to its large surface tension. Here, an intriguing synergistic oxidation-driven liquid metal fractal phenomenon was discovered and the general mechanisms were interpreted, which provides a new strategy for manipulating liquid metal. Experimental results demonstrate that the liquid metal placed on the graphite plate exhibited fractal characteristics with the addition of hydrogen peroxide. Here, it is of significance that hydrogen peroxide and graphite plates synergistically oxidize liquid metal. In addition, we predicted that liquid metal fractals can also be achieved on other eligible substrates based on the proposed general mechanism, which was confirmed by relevant experiments. Furthermore, the fractal dimensions of liquid metal fractal pattern were obtained and evaluated, distinguishing the synergistic oxidation-driven liquid metal fractals from the voltage-driven liquid metal fractals. Besides, we initially gave the best concentration range in which dendritic fractals can occur in order to guide practice. The ability to achieve liquid metal fractals promises rich opportunities in freely driving the liquid metal for soft machines and manufacturing the shape-reconfigurable electronic circuits.
Keywords: Fractal phenomenon; Liquid metal; Non-equilibrium thermodynamics; Soft matter; Spontaneous spreading; Synergistic oxidation.
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