The microstructured surface exhibit

The microstructured surface exhibits superhydrophobicity after the integration of a nanostructured coating. Fluorinated fractal nanoclusters of silica were used as a model superhydrophobic nanomaterial (Fig. 3a, Supplementary Figs. 14, 15). Upon repeated scraping using a steel blade, the microstructure showed excellent resistance to the vertical pressure and the shear force, and the fractal nanostructures in between the microstructure framework remained intact (Fig. 3b). It is notable that the abrasion removes the fluorinated silane layer from the top of the microstructures, which alters the local wetting properties of the surface from hydrophobic (θY = 115 ± 1°) to hydrophilic (θY = 45 ± 0.5°, Supplementary Table 1). Using laser scanning confocal microscopy we confirmed that the air–water–solid composite interface at the microscale is very stable, because the air–liquid–solid three-phase contact line is supported by nanoscale superhydrophobic materials (Fig. 3a, c).The water-repellent nanostructures can prevent the sagging of the liquid–air interface caused by the Laplace pressure, and the entire system remained in the constrained equilibrium Cassie–Baxter state