Anisotropic Superhydrophobic Properties of Bioinspired Surfaces by Laser Ablation of Metal Substrate inside Water

Abstract

AbstractWater droplet unidirectional adhesion, wetting, and transport on the asymmetric superhydrophobic surfaces have attracted much research interest in theory analyses and applications. In this study, inspired by the butterfly wings and lotus leaf, a novel anisotropic superhydrophobic surface with different tilt angles of the wedge‐shaped structures is prepared on aluminum surfaces via laser ablation inside water. It is demonstrated experimentally that the resistant force of water droplets on the bioinspired surfaces is different along the tilt direction of the wedge‐shaped structure and the inverse direction. The sliding and bouncing behaviors of water droplets on different bioinspired wedge‐shaped structure surfaces are simulated and tested to understand better the mechanism of the rolling and bouncing droplets induced by asymmetric wedge‐shaped structures. Furthermore, the effect of the tilt wedge‐shaped structures on the anisotropic superhydrophobic properties is revealed from the mechanical point of view. The relationship between the anisotropic superhydrophobic properties and the tilt angle of the wedge‐shaped structure is investigated.