Ang Barbara Ting Wei, Zhang Jiong, Lin Gabriel Jiajun, Wang Hao, Lee Wee Siang Vincent, Xue Junmin
ACS Appl Mater Interfaces. 2019 Jul 31;11(30):27464-27469. doi: 10.1021/acsami.9b08460. Epub 2019 Jul 16.
Harvesting water from high humidity conditions is an attractive strategy toward strengthening water security due to its cost-effective and zero-energy mechanism. To facilitate this process, bio-inspired microstructures with heightened water accumulating ability are typically affixed onto atmospheric water harvesters. However, because of this surface morphology type harvester design, there is an inherent partition of regions with different water accumulating abilities: the active water harvesting region (AWHR) and passive water harvesting region (PWHR). Most of the water harvested by such water harvesters is usually attributed to the AWHR, while a large amount of uncollected water is present in the PWHR as numerous small water droplets that are prone to re-evaporation. This lack of PWHR utilization may be considered as the Achilles' heel toward optimal water harvesting. Hence, in this work, a cascading effect was proposed with a microstructure design to induce water harvesting from both AWHR and PWHR. The "clearing" of PWHR columns was demonstrated via a cascading effect, contributing to ca. 3 times more water harvested as compared to the unmodified water harvester. The successful demonstration of this cascading effect highlights the necessity of considering PWHR in the future water harvester designs so as to achieve efficient water harvesting.
由于其具有成本效益且零能耗的机制，从高湿度条件下收集水是加强水安全的一种有吸引力的策略。为了促进这一过程，通常将具有增强集水能力的仿生微结构附着在大气集水器上。然而，由于这种表面形态类型的集水器设计，存在着具有不同集水能力区域的固有划分：主动集水区域（AWHR）和被动集水区域（PWHR）。这种集水器收集的大部分水通常归因于AWHR，而大量未收集的水以大量易于重新蒸发的小水滴形式存在于PWHR中。对PWHR的这种利用不足可被视为实现最佳集水的致命弱点。因此，在这项工作中，提出了一种级联效应，并通过微结构设计来诱导从AWHR和PWHR收集水。通过级联效应展示了PWHR柱的“清理”，与未改进的集水器相比，收集到的水量增加了约3倍。这种级联效应的成功展示凸显了在未来集水器设计中考虑PWHR以实现高效集水的必要性。
