Nature-Inspired Design Strategies for Efficient Atmospheric Water Harvesting

The accelerating global scarcity of freshwater, driven by rapid economic growth, environmental degradation, and climate change, has heightened the urgency for the development of advanced atmospheric water harvesting (AWH) strategies. Earth's atmosphere contains an enormous reservoir of ≈13 trillion tons of water, exceeding the volume of all accessible surface freshwater, yet it remains vastly underutilized. Effectively utilizing the atmospheric water requires efficient capture and release strategies that can function under diverse climatic conditions. Through millions of years, organisms in both arid and humid environments have evolved specialized structures or surfaces to capture water directly from the atmosphere. This review highlights recent advances in bioinspired AWH systems, emphasizing how structural motifs such as wettability gradients, directional transport, and hierarchical porosity are translated into engineered fog-collection and vapor-sorption systems, leading to enhanced water uptake, accelerated transport, and energy-efficient release. By integrating insights from various complementary approaches, the design principles and fabrication strategies that bridge biological inspiration with practical, high-efficiency AWH for scalable solutions to address the global water challenges are outlined.