Inspired by the adhesion differences on the surfaces of fresh and dried rose petals, a rose bionic self-cleaning fog collector (RBSC) was designed and prepared to realize a self-driven fog harvesting function. The droplet detachment iteration rate was revealed by the regulating mechanism of the surface adhesion force of the RBSC and the influence of bionic texture parameters, as demonstrated through the fog harvesting experiment and droplet detachment failure analysis. Through the surface adhesion force regulation, the probability of droplet dissipation with the airflow is reduced by increasing the falling droplets' mass, and the single surface fog capture efficiency is up to 740 mg cm-2 h-1. With the adhesion gradient regulation, the composite hexagonal patterned surface achieves a water collection efficiency of 960 mg cm-2 h-1, which is a 243% improvement compared with that of a slippery surface and is superior to the efficiencies of both circular and 90° square patterns. This is due to the fact that the composite hexagonal patterned surface ensures that the water droplets converge at the center while increasing the distance between the droplets, improving the stability of droplet detachment. Compared to the stainless steel surface, the RBSC exhibits excellent self-cleaning performance, with the impurity deposition rate reduced by 91.2%. The multi-inspired strategy optimizes the entire harvesting process, offering a promising solution to the water crisis in arid regions.
Keywords: adhesion tunable; fog harvesting; multibioinspired characteristics; self-cleaning; wettability gradient.