Fabrication of Durable Superhydrophobic Surfaces with a Mesh Structure and Drag Reduction by Chemical Etching Technology

Superhydrophobic surfaces are critical in the marine industry because ships and underwater vehicles are constantly exposed to hydrodynamic friction and biofouling during operation, which can negatively affect their efficiency and increase operating costs. To address these challenges, this study proposes a straightforward method for fabricating stable superhydrophobic surfaces. By modifying nano-copper oxide on a microstructure substrate, a coating exhibiting exceptional hydrophobicity, designated as 100-SHB, was successfully developed. The 100-SHB has a water contact angle of about 163.0° and a sliding angle of about 2.0°, which is highly repulsive to water droplet impact. Furthermore, 100-SHB maintained its superhydrophobic properties under rigorous testing, including water puncture resistance, sandpaper abrasion, and ultrasonic damage tests. The incorporation of a lithography-based network structure further enhanced the mechanical stability of the surface, highlighting its robustness. In ship model experiments, the surface demonstrated a remarkable drag reduction rate of 64.2%. This environmentally friendly, simple, and scalable fabrication method represents a significant advancement toward practical implementation in the marine industry and holds promise for expanding applications in non-wetting-related fields.