Imprinting nanostructures on metallic surface via underwater electrical wire explosion shock waves

Fabricating nanostructures on metallic surface is relevant to various applications, and there is growing interest in developing new methods that balance accuracy, throughput and cost. In this work, a novel method, underwater electrical wire explosion shock imprinting (UEWESI), is proposed as a versatile one-step method for imprinting large-area surface nanostructures on both thin and thick substrates. Using a polycarbonate mold, the 10 μm thickness and 40 × 40 mm² area aluminium foil was uniformly imprinted via single copper wire explosion at a 12 mm standoff distance and 1.8 kJ electrical stored energy, with a fidelity up to 80 %. A periodic imprinting mechanism based on the stress evolution in the substrate was proposed to explore the physical process and explain the effects of standoff distance, shock wave pulse width, substrate thickness and layer arrangement on imprinting performance. Additionally, a scaled-up variant of UEWESI utilizing an exploding wire array was introduced, which generates a large-area planar shock wave front through the convergence of individual shock waves, further enhancing imprinting performance. This work offers a promising alternative for large-scale fabrication of nanostructures on metallic surfaces, with potential applications in flexible electronics, rechargeable batteries, plasmonics and other related fields.