Enhancing fog harvesting efficiency with a multi-object-coupled bio-inspired surface.

The global freshwater crisis poses a substantial threat to sustainable development, driving urgent demand for advanced atmospheric water harvesting technologies. While bio-inspired fog collectors have shown potential, conventional single-scale architectures often exhibit suboptimal performance due to inadequate coordination between droplet nucleation and transport. Here we present a multi-object-coupled venation-shaped patterned surface (MVSS) fabricated through laser-etching of filter paper/polydimethylsiloxane composite films. By synergistically integrating three bio-inspired mechanisms: (i) heterogeneous wettability patterns mimicking desert beetle elytra, (ii) conical spine arrays inspired by Opuntia histophysiology, and (iii) hierarchical venation networks derived from plant leaf, we establish a multi-stage phase-transition process that enhances fog harvesting efficiency through coordinated surface energy gradients and Laplace pressure modulation. The wettability contrast enables selective droplet nucleation, while the conical geometry generates asymmetric contact line pinning that drives directional transport. The hierarchical branching network minimizes hydraulic resistance through optimized flow path partitioning, achieving rapid drainage while suppressing edge water accumulation. This multi-scale synergy yields a record water collection rate of 1033 ± 28.2 mg cm h. Our findings elucidate the critical role of structure-property coordination in fog water collection, providing a generalized design paradigm for developing high-efficiency atmospheric water harvesters. The fabrication strategy combining scalable laser processing with bio-composite materials suggests promising pathways for arid region deployment.