Jia Runqi, Jing Yongxin, Chu Hongchen, Peng Ruwen, Wang Mu, Lai Yun
National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China.
School of Physics and Technology, Nanjing Normal University, Nanjing, 210023, China.
Adv Sci (Weinh). 2024 Oct;11(39):e2404010. doi: 10.1002/advs.202404010. Epub 2024 Aug 21.
Dewdrops, the droplets of water naturally occurring on leaves and carapaces of insects, are a fascinating phenomenon in nature. Here, a man-made array of dewdrops with arbitrary shapes and arrangements, which can function as an electromagnetic metasurface, is demonstrated. The realization of the dewdrop array is enabled by a surface covered by a tailored pattern of hydrophilic and hydrophobic coatings, where tiny droplets of water can aggregate and form dewdrops on the former. Interestingly, this metasurface made of dewdrops can be modulated by the condensation and evaporation process. By increasing relative humidity and decreasing temperature, the dewdrop metasurface is gradually formed with increasing amounts of water. While the reverse operation can make it completely disappear. This idea is demonstrated through two examples with different functions of dynamically controllable microwave absorption and scattering. The work shows a principle to construct functional electromagnetic devices with dewdrops, as well as a mechanism of dynamic control based on condensation and evaporation, promising unprecedented applications.
露珠是自然出现在叶片和昆虫甲壳上的水滴，是自然界中一种迷人的现象。在此，展示了一种人造的、具有任意形状和排列的露珠阵列，其可作为一种电磁超表面发挥作用。露珠阵列的实现得益于覆盖有定制亲水性和疏水性涂层图案的表面，微小的水滴能够在亲水性涂层上聚集并形成露珠。有趣的是，这种由露珠构成的超表面可通过凝结和蒸发过程进行调制。通过增加相对湿度和降低温度，随着水量增加，露珠超表面逐渐形成。而反向操作可使其完全消失。通过两个具有动态可控微波吸收和散射不同功能的示例对这一想法进行了演示。这项工作展示了一种用露珠构建功能性电磁器件的原理，以及一种基于凝结和蒸发的动态控制机制，有望带来前所未有的应用。
