Efficient direction-independent 3D spiral fog collector.

Inspired by the natural structures of cacti and desert beetles, a novel three-dimensional (3D) high-efficiency fog collector is proposed. This design integrates a unique macro-structural configuration with a surface wettability gradient that remains independent of the fog flow direction. The fog collector adopts an integral spiral structure, with superhydrophilic triangular protrusions uniformly distributed across its surface. Under optimized design conditions, with a folding angle of 60 degrees, the collector features 23 superhydrophilic protrusions, each measuring 2.5 × 5 mm. Under these conditions, the fog collection efficiency reaches 0.5057 g cm^-2 min^-1. Furthermore, to assess the practical feasibility of the fog collector, a series of experiments, including sand impact and chemical resistance tests, were conducted. The experimental results show that the contact angle of the fog collector's surface remains high, indicating its excellent stability and durability. The fog collector not only uses a low-cost aluminum plate as the base material but also incorporates a simple and efficient preparation process, significantly enhancing its design feasibility and practicality. The results presented in this study offer a novel approach to designing high-efficiency fog collectors that are unaffected by the direction of fog flow.