Wettability-Patterned Meshes for Efficient Fog Collection Enabled by Polymer-Assisted Laser Sintering

Water collection from fog has been considered as a meaningful strategy to alleviate the scarcity of fresh water in some arid and semi-arid lands. Due to the specific wettability pattern on the back, Stenocara beetles show amazing capability for water capture from fog. Various biomimetic flat surfaces with wettability have been reported in the last decade. However, it is still a great challenge to accurately construct a patterned surface on a mesh, which is the common material in the practical application of fog collection. Herein, a facile and easy-to-operate strategy for surface modification on a stainless-steel (SS) mesh based on polymer-assisted laser sintering has been developed. A certain polymer film can be chosen to obtain different wettabilities because of the elemental composition and microstructure after laser sintering. Laser sintering following pre-design contributed to accurate control of the pattern geometry, size, and site. A bio-inspired pattern mesh with isolated triangular superhydrophobic regions and hydrophilic channels was fabricated for water collection from fog flow. Due to the good balance of water droplet capture, growth, and removal, the rationally designed SS mesh showed a satisfactory collection rate as high as 177.65 mg cm–2 h–1, which was a nearly 16-fold increase compared to that of the pristine SS mesh. The obtained mesh also showed high stability not only in long-term applications but also in several cycles of regeneration. Based on the outstanding performance of fog water collection, the patterned SS mesh could be of great value in practical applications. Furthermore, the polymer-assisted laser sintering strategy for surface modification on mesh could potentially be applied in various fields for high efficiency and scalability.