Preserving exposed hydrophilic bumps on multi-bioinspired slippery surface arrays unlocks high-efficiency fog collection and photocatalytic cleaning.

Abstract

The efficiency of fog collection technologies is inherently hindered by the long-standing dilemma of capture vs. transportation balance. Inspired by nature, we address this issue by preserving hydrophilic bumps on slippery liquid-infused porous surfaces (SLIPS) through an underwater infusion strategy, creating a super-slippery fog collector with multi-scale biomimetic structures. This surface combines features from beetle carapaces and pitcher plant surfaces, enabling rapid initial water capture on hydrophilic bumps and efficient droplet transport. As a result, we develop the most efficient fog-collecting surface reported to date, harvesting 5000-60000 mg/cm² per hour with fog flow rates ranging from 300-1500 mL/h. By macroscopically scaling and optimizing, we construct an integrated 3D fog collecting device capable of harvesting over 660 g of water in 500 minutes. Further integrating TiO₂ into the bumps imparts the ability for simultaneous water collection and purification without sacrificing collection efficiency. Our work reveals that resolving the capture-transport dichotomy is key to achieving high-efficiency fog water collection.