Enhanced Fog Harvesting via Synergistic Regulation of the Entire Process on a Multi-Bioinspired Patterned Surface

Abstract

Freshwater scarcity has become an urgent global issue. Bioinspired fog harvesting is a promising route to freshwater supply, whereas conventional bioinspired surfaces merely optimize partial procedures independently, severely restricting fog harvesting efficiency. Herein, inspired by cactus spines, Sarracenia trichomes, spider silk, and leaf veins, we rationally designed a multi-bioinspired patterned surface (MBPS) featuring nanoneedles, wettability-gradient microchannels, and vein-like networks to synergistically regulate the entire harvesting process. Specifically, once a continuous water film forms within the microchannels, fog droplets effectively captured by dense nanoneedles, upon contacting the hydrophilic pattern, are rapidly drawn into the microchannels and directionally transported toward the designated collection area via the interconnected network under the combined effect of multiple driving forces. This unique harvesting mode synergizes fog capture, droplet coalescence, and transport, endowing the MBPS with a high efficiency of 2.52 g cm-2 h-1 as well as excellent cyclic stability. Such multi-effect synergy further facilitates efficient fog harvesting.