Bioinspired Asymmetric Surface Property of Functionalized Mesh to Maximize the Efficiency of Fog Harvesting

Water scarcity in many countries on earth has inspired scientists to seek other resources of freshwater. Desalination, as one of the most commonly used approaches, is energy consuming and has faced a number of environmental difficulties. On the other hand, natural species, plants and insects, have developed their own modalities of securing fresh water by harvesting it from the atmospheric fog and humidity. The current study investigates the fabrication of bioinspired mesh membranes for fog harvesting. The mesh membranes are coated using a simple dip coating procedure with various extents of TiO₂-PMMA hybrid structure that provides a composite structure of mixed degrees of wettability. Depending on the initial concentration of PMMA, partially and completely covered mesh membranes were prepared. The coated mesh membranes resemble Spider silk in their architecture and in their surface topography to other desert natural species. A homogeneous distribution of the TiO₂ NPs within the PMMA coating was reflected on a spectrum of hydrophilic and hydrophobic domains. The fabricated mesh membranes are durable and have been shown to harvest water from fog at a rate of 32–45 L/m² per hour, hence securing a sustainable supply of fresh water for all aspects of life.