Nature-Inspired Windmill for Water Collection in Complex Windy Environments

Nature-inspired water collection technology has been well-recognized as an effective solution for relieving water shortage hardships, and yet remains challenging when being used in an actual natural environment. In this work, we have successfully developed a promising water-collecting windmill that can be used in complex windy environments, by taking integrative inspiration from the liquid-manipulation strategies adopted by rice leaves, cacti, Nepenthes pitcher plants, and butterflies. The unique directional grooves on the blade surface with ridge-like walls with a shape gradient, combined with a molecular slippery layer, are crucial for not only water deposition but also directional drainage in water collection. Besides, the engineering design of rotatable blades turns the adverse effect of strong winds into a positive one, along with the nature-inspired surface topography and physicochemical property. Such a novel windmill has shown unprecedented water-collecting performance in a static environment, in strong wind, and in intermittent wind. Furthermore, the windmill can sense the wind-blowing direction and adjust its facing direction accordingly to ensure maximum utilization of wind power. It is believed that this work will bring a broad guiding significance to the design of smart water-harvesting materials and devices for application in more complex situations.