Leaf Vein-Inspired\nSuperhydrophilic Microchannels\nfor Sustainable Fog Collection

Fog collection is a promising solution for mitigating\nthe urgent\nwater shortage around the world. Despite the delicate design of various\nbionic fog harvesting surfaces with prowess to enable fast fog capture\nand programmed water transport, achieving sustainable and efficient\nfog collection by regulating the macroscale surface refreshment efficacy\nremains rarely concerned yet is effective. Here, we proposed a bioinspired\nstructural design to achieve significant improvement on the surface\nrefreshment efficacy to 46.47%, nearly 5 times larger than that of\nconventional design. Specifically, we constructed superhydrophilic\nvein-like microchannels on a superhydrophobic brass surface by using\nlaser texture technology and hydrothermal treatment. Our microchannel\ndesign acts as a “highway” for synergically transporting\nand converging the collected fog droplets, as well as rapidly refreshing\nlarge surface area for the subsequent fog collection, reminiscent\nof the leaf veins responsible for the persistent mass transport between\nplant tissues. The practical implementation also convinced our design\nof a maximum water collection efficiency of up to 506.67 mg cm<sup>–2</sup> h<sup>–1</sup> and a long-term performance\nstability within a 10 h test. Our design is generic to most of the\nfog harvesting materials, showing great application potential for\nefficient atmospheric fog collection.