Underwater superaerophobicity and superaerophilicity of the femtosecond laser-structured aluminum surface. (a) Laser-induced hierarchical microgrooves on the aluminum surface. (b) 3D profile of the hierarchical microgrooves. (c, d) High-magnification SEM images of the microstructure produced by femtosecond laser ablation. (e) Laser-structured surface in water. (f) Fluorinated rough aluminum surface in water. (g) Bubble on the laser-structured surface underwater. (h) Bubble on the fluorinated rough aluminum surface underwater. Reproduced from [122
] with the permission.