Small Structures, Big Droplets: The Role of Nanoscience in Fog Harvesting.

Designing materials for water harvesting has gained much attention in recent years as water scarcity continues to be one of the biggest problems facing mankind. In this issue of ACS Nano, Xu et al. propose a new device for harvesting water from fog. They use conically shaped copper wires with periodic roughness to enhance condensation and transport of water drops. While the periodic roughness enhances drop coalescence and motion, the conical shape of the wires guides the drops in a specific direction. Together, a self-sustained water-harvesting system is described which does not require additional external stimulus but makes use of a smart design and economic production.