Multiscale Microflower Structured Superhydrophobic Surface via Electrostatic Air Spray

Superhydrophobic surfaces with microstructures and multifunctionality have attracted intense research interest. Herein, a multiscale microflower structured surface (MMSS) was successfully fabricated by electrostatic air spray. To systematically study the preparation process, the influences of different electrostatic voltages, solution ratios, soaking time, spray distances, and spray time on surface morphology and hydrophobicity were analyzed. The surface has good superhydrophobic properties with a water contact angle of 162.3°, which allows the surface to be self-cleaning and antifouling. The surface hydrophobicity can be maintained after various mechanical and chemical damages. To overcome the limitation that existing droplet manipulation relies on special materials and surfaces, a new and universal droplet transport method is presented to successfully perform nondestructive droplet manipulations, which relies on external forces and droplet deformation to drive droplets. Therefore, this paper represents a different approach from previous studies of superhydrophobic surfaces and provides a new way to achieve dynamic droplet manipulations. These results indicate that the multifunctional MMSS will be widely used in industrial droplet transportation and self-cleaning applications.