Laser-Constructed Bionic Composite Fog-Collecting Surfaces with Efficient Nucleation Sites and Enhanced Water Transport

Fog collection effectively alleviates the current freshwater shortage; thus, enhancing its efficiency is crucial. Here, we report a novel bionic fog collection surface (Al@B-V) comprising composite superhydrophobic bumps integrated with superhydrophilic V-channel grooves. This surface, which has efficient fog nucleation points and enhanced water transport capabilities, effectively balances fog capture and water transport during the collection process, thereby achieving high-efficiency fog collection. Compared to ordinary aluminum-based surfaces, Al@B-V achieves a fog collection efficiency of up to 3.08 g·cm^-2·h^-1, three times higher than the original aluminum-based surface. Furthermore, the V-channel groove proposed in this study exhibits a water transport speed of up to 165 mm·s^-1, which is remarkably approximately 80 times faster than the commonly used U-channel groove. Additionally, this V-channel groove can overcome gravity, transporting approximately 10 μL of liquid to the top even when placed at 90° inclination. It can directionally transport 10 μL of liquid over a distance of up to 151 mm on a plane. This novel microgroove design can be effectively applied in various fields, including liquid collection, directional transport, seawater desalination, microfluidics, and drug delivery.