One-step method using laser for large-scale preparation of bionic superhydrophobic & drag-reducing fish-scale surface

Abstract In this study, four bionic fish-scale models were extracted and produced based on the microscopic morphology and the arrangement of scales on the body of Sciaenops ocellatus. A simple, quick and low-cost method using laser was introduced for fabricating the bionic fish-scale surface on aluminum (Al) alloy. Under the action of laser beams, the fish-scale morphology with inclined surface was obtained by controlling the density of laser path and processing times. Biomimetic fish-scale surfaces with different sizes were produced through adjusting the four ratios of fish scale graph. Then wettability test was performed on different samples. Our results showed that all the samples were hydrophobic and the sample with 100% zoom ratio demonstrated excellent superhydrophobicity and low adhesion. Furthermore, we tested the drag reduction performance of the sample with zoom ratio of 100%. The experimental results indicated that under different flow conditions, the sample exhibited different performance values in drag reduction, and the drag reduction rate could reach 4.814% under laminar conditions. This study provided a simple method from the perspective of bionics to fabricate a bionic superhydrophobic surface with drag reduction performance, providing positive guidance for the fabrication of underwater drag-reducing surface.