Bio-Inspired Fog Harvesting Meshes: A Review

Freshwater scarcity has become a critical global challenge affecting some of the most vulnerable populations. In response, significant effort has focused on ways to increase access to this precious resource. Within the context of geographical, cultural, political, and technological factors governing freshwater availability, atmospheric water harvesting (AWH) has demonstrated tremendous promise to help address these shortages. Specifically, mesh-based fog harvesters have received considerable attention for their passive qualities compared with their energy-dependent technological siblings (sorbents, condensation, etc.), yet their specific water yield (SY) has developed only modestly in recent decades. While the plant and animal kingdom provide diverse examples of passive fog collection, and science has developed a remarkable understanding of these processes, much of this knowledge has yet to be translated practically at scale. This is partially due to challenges in mass-producing complex (often micro-scale) structures observed in nature. Fortunately, manufacturing technology is catching up with scientific understanding, especially at the scale of mesh design. To this end, the review begins by surveying bioinspired research in fog harvesting. Afterward, this study identifies milestones in developing bioinspired fog harvesting meshes, concluding in a discussion of future mesh research opportunities connecting bioinspiration and emerging advanced manufacturing techniques. Fog harvesting has emerged as a valuable tool for addressing global water scarcity. While recent science has explored fog harvesting materials at a nano-to-fiber scale, insufficient emphasis is placed on droplet behavior at the mesh-material scale. Here, opportunities for significant advancement in the design of fog harvesting meshes are examined, with a particular focus on biomimetic insight.image