Experimental Investigation on the Droplet Stability of Superhydrophobic Mesh

Superhydrophobic surfaces could repel water due to the capillary force associated with surface roughness, which has a large range of applications, such as underwater drag reduction, heat transfer enhancement, oil/water separation, and so on. However, the engineering applications of superhydrophobic surfaces rely on the stability of the superhydrophobic surfaces. In this study, a hydrophilic metal mesh was modified to be superhydrophobic. The resulting superhydrophobic mesh was designed as a bowl capable of holding water without leaking and as a boat floating on top of water without sinking. The stability of an impacting droplet on a superhydrophobic mesh was investigated using both experiments and theoretical analysis. It was demonstrated that the capillary force is able to prevent water from passing through the mesh and maintain the stability of the air-water interface under dynamic pressure. Furthermore, a theoretical model was developed to diagnose the stability of the air-water interface on the superhydrophobic mesh when in contact with water, and the results are consistent with the experimental findings. The results of this work can be utilized to design robust superhydrophobic meshes and advance the field of droplet manipulation.