Magnetically induced fog harvesting via flexible conical arrays

Water is the driving force of all nature. Securing freshwater has been one of the most important issues throughout human history, and will be important in the future, especially in the next decade. Fog is ubiquitous in nature and is therefore considered as an alternative and sustainable freshwater resource. Nature has long served as a source of inspiration to develop new fog-harvesting technologies. However, the collection of freshwater from static fog is still a challenge for the existing bio-inspired fog-harvesting systems. Herein, magnetically induced fog harvesting under windless conditions through the integration of cactus-inspired spine structures and magnetically responsive flexible conical arrays is reported. Under an external magnetic field, static fog can be spontaneously and continuously captured and transported from the tip to the base of the spine due to the Laplace pressure difference. This work demonstrates the advantage of collecting fog water, especially in windless regions, which provides a new avenue for fog harvesting and can serve as a source of inspiration to further optimizations of existing fog-water-harvesting strategies. A magnetically induced fog collector is fabricated through the integration of cactus-inspired spine structures and magnetically responsive flexible conical arrays. Quasistatic fog water can be spontaneously and continuously captured and directionally transported, driven by the external magnetic field and the Laplace pressure difference. This work opens a new avenue for fog-harvesting systems under windless conditions.