Li Jing, Ran Ranjiangshang, Wang Haihuan, Wang Yuchen, Chen You, Niu Shichao, Arratia Paulo E, Yang Shu
Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA.
Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, PA, 19104, USA.
Nat Commun. 2021 Sep 16;12(1):5484. doi: 10.1038/s41467-021-25764-4.
To address the global water shortage crisis, one of the promising solutions is to collect freshwater from the environmental resources such as fog. However, the efficiency of conventional fog collectors remains low due to the viscous drag of fog-laden wind deflected around the collecting surface. Here, we show that the three-dimensional and centimetric kirigami structures can control the wind flow, forming quasi-stable counter-rotating vortices. The vortices regulate the trajectories of incoming fog clusters and eject extensive droplets to the substrate. As the characteristic structural length is increased to the size of vortices, we greatly reduce the dependence of fog collection on the structural delicacy. Together with gravity-directed gathering by the folds, the kirigami fog collector yields a collection efficiency of 16.1% at a low wind speed of 0.8 m/s and is robust against surface characteristics. The collection efficiency is maintained even on a 1 m collector in an outdoor setting.
为应对全球水资源短缺危机，一个有前景的解决方案是从雾等环境资源中收集淡水。然而，由于含雾气流在收集表面周围偏转时的粘性阻力，传统雾收集器的效率仍然很低。在此，我们表明三维厘米级的剪纸结构可以控制气流，形成准稳定的反向旋转涡旋。这些涡旋调节进入的雾团轨迹，并将大量水滴喷射到基底上。随着特征结构长度增加到涡旋大小，我们大大降低了雾收集对结构精细度的依赖。与褶皱的重力导向聚集相结合，剪纸雾收集器在0.8米/秒的低风速下产生了16.1%的收集效率，并且对表面特性具有鲁棒性。即使在室外环境中的1米收集器上，收集效率也能保持。
