Abstract: Drag reduction surfaces have been receiving increasing attention in various fields such as aviation, aerospace, and maritime due to their significant role in reducing energy consumption. And achieving high-efficiency drag reduction is significant. After hundreds of millions of years of natural selection, animals and plants in nature have developed numerous drag-reduction surfaces. The biomimetic micro/nanostructured surfaces by studying drag-reduction organisms, such as sharks, offer an innovative approach for efficient drag reduction. This review systematically summarizes the research progress of biomimetic micro/nanostructured surfaces for drag reduction and elucidates the morphological features and drag reduction mechanisms of shark-inspired surfaces and other fish-inspired surfaces. This work also describes the machining methods for biomimetic micro/nanostructured drag-reduction surfaces, including high-energy beam machining, surface etching, ultra-precision machining, 3D printing, and bio-replication technologies. Furthermore, it briefly outlines the practical applications of existing biomimetic drag-reduction surfaces in aerospace, sports events, pipeline transportation, and other areas. Finally, based on the analysis and summary of research progress, manufacturing methods, and practical applications, this study discusses the prominent advantages of biomimetic micro/nanostructured drag-reduction surfaces. It highlights the current status and challenges of machining technologies.

Key words: bionics, micro/nanostructures, surface drag-reduction, shark skin, ultraprecision machining