Anti-icing aluminum alloy surface with multi-level micro-nano textures constructed by picosecond laser

Highlights: • Micro-nano tertiary structures were constructed on aluminium alloy surface through picosecond laser processing. • The laser processed surfaces exhibit superhydrophobicity. • These hierarchically textured surfaces exhibit delayed frozen time and dropped frozen temperature of icing. -- Abstract: Anti-icing surface is crucial to the safety of aircraft, power line, mechanical apparatus and other important devices, while the current superhydrophobic surfaces are facing dilemmas of short lifespan, poor stability and complex processing, owing to the low-strength of coating or required post-chemical modification. Here, considering the pivotal role of micro-nano textures in enhancing the stability and lifespan of ice-repellent surfaces, grating textures with micro-nano tertiary structures on aluminum alloy surface were directly constructed through picosecond laser processing. These hierarchically textured surfaces exhibit low-temperature-adaptive water repellency, which delays frozen time and drops frozen temperature. The above scenario was fundamentally understood from viewpoint of both wettability and thermodynamics. These results are extremely important for fabricating superhydrophobic metallic surface with long lifespan and delayed frozen performance without any chemical modification.