Low-Cost Fabrication of Large-Area Broccoli-Like Multiscale Micro- and Nanostructures for Metallic Super-Hydrophobic Surfaces with Ultralow Water Adhesion and Superior Anti-Frost Ability

Metallic super-hydrophobic surfaces with ultralow water adhesion are essential for a wide variety of applications, such as enhanced condensation heat transfer and anti-icing applications. Broccoli-like multiscale micro- and nanostructures composed of four different microscale and nanoscale features are fabricated on different metal surfaces by an inexpensive nanosecond laser system in this study. The surface shows high stability during evaporation, and the surface water adhesion of this structure is only 1.4 +/- 0.4 mu N, much lower than that of typical reported surfaces. Slight changes to the surface morphology results in an increase in the surface water adhesion, and this unique broccoli-like surface structure shows an much better anti-frost ability compared with similar structures with slightly higher water adhesion. The results provide a cost-effective method to achieve large-area metallic super-hydrophobic surfaces with extremely low water adhesion and superior anti-frost ability.