Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011, United States.
School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China.
ACS Appl Mater Interfaces. 2022 Oct 5;14(39):44782-44791. doi: 10.1021/acsami.2c09280. Epub 2022 Sep 21.
With the recent threat of climate change and global warming, ensuring access to safe drinking water is a great challenge in many areas worldwide. Designing functional materials for capturing water from natural resources like fog and mist has become one of the key research areas to maximize the production of clean water. From this aspect, nature is a great source for designing bioinspired functional materials as some of the plant leaves and animal exoskeletons can harness water and then store it to save themselves from arid, xeric conditions. Inspired by the beetle, we have designed a composite surface structure with periodic islands made of aluminum microparticles surrounded by poly(dimethylenesiloxane) (PDMS). An acoustic tweezer-based method was used to fabricate the bioinspired composite structures, where surface acoustic waves at specific frequencies and amplitudes are applied to align the microparticles as islands in the polymer matrix. An oxygen plasma etching step was applied to expose the microparticles on the PDMS surface. The average water harvesting efficiencies for structures made with 120 and 80 kHz acoustic frequencies and 1 hour etching time were found to be 9.41 and 8.84 g cm h, respectively. The acoustically patterned biomimetic composite surface showed higher water harvesting efficiency compared with completely hydrophobic PDMS and hydrophilic aluminum surfaces, demonstrating the advantages of the bioinspired composite material design and acoustic-assisted manufacturing technique. The biomimetic fog water harvesting material is a promising avenue to fulfill the demand for a cost-effective, sustainable, and energy-efficient solution to safe drinking water.
随着气候变化和全球变暖的威胁，确保获得安全饮用水是全球许多地区面临的巨大挑战。设计从雾和霭等自然资源中捕获水的功能材料已成为最大限度地生产清洁水的关键研究领域之一。从这个角度来看，大自然是设计仿生功能材料的重要源泉，因为一些植物叶子和动物外骨骼可以利用水并储存水，以避免干旱和干燥条件。受甲虫的启发，我们设计了一种具有周期性岛屿的复合表面结构，这些岛屿由铝微粒子组成，周围是聚二甲基硅氧烷（PDMS）。我们使用基于声镊子的方法来制造仿生复合结构，其中在特定频率和幅度的表面声波被用来将微粒子排列成聚合物基质中的岛屿。然后进行氧等离子体刻蚀步骤，以将微粒子暴露在 PDMS 表面上。结果发现，在 120 kHz 和 80 kHz 声频率下，以及 1 小时刻蚀时间下，结构的平均水收集效率分别为 9.41 和 8.84 g cm h。与完全疏水的 PDMS 和亲水的铝表面相比，声图案化仿生复合表面显示出更高的水收集效率，这证明了仿生复合材料设计和声辅助制造技术的优势。仿生雾水采集材料是满足对经济高效、可持续和节能的安全饮用水解决方案的需求的有前途的途径。
