Lian Jiaoyuan, Li Wei, Yang Ling, Li Hegeng, Deng Qiyu, Zhu Hengjia, Zhang Yiyuan, Fang Nicholas X, Wang Liqiu
Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, China.
Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hong Kong, China.
Proc Natl Acad Sci U S A. 2025 May 13;122(19):e2421589122. doi: 10.1073/pnas.2421589122. Epub 2025 May 8.
Liquid manipulation is ubiquitous in nature and engineering, enabling controllable and efficient liquid delivery. Conventional understanding of liquid manipulation relies on inhomogeneous chemical modifications or single-scale structure design. Here, we present how water is directionally navigated and spontaneously reallocated at high efficiency via the cross-scale topology on leaves. These leaves feature transversely curved lanceolate macrostructures decorated by a layer of microtrichomes with varied morphologies. The macrostructure creates a lanceolate effect in the transport direction for fundamental navigation. At the same time, the microtrichomes serve dual functions: constructing a self-wetting superhydrophilic surface to facilitate the water transport speed and implementing water spreading in the opposite direction for autonomous reallocation. We explain the multiscale transport behavior through theoretic analysis and finite element simulations. Our findings demonstrate how cross-scale topographies jointly function in efficient autonomous fluid manipulation, with potential applications such as droplet driving, fog harvesting, and seawater desalination, offering pathways for improving liquid processing efficiency and reducing energy consumption.
液体操控在自然界和工程领域中无处不在，可实现可控且高效的液体输送。传统的液体操控理解依赖于非均匀化学修饰或单尺度结构设计。在此，我们展示了水如何通过叶片上的跨尺度拓扑结构高效地定向流动和自发重新分配。这些叶片具有横向弯曲的披针形宏观结构，上面装饰着一层形态各异的微毛。宏观结构在传输方向上产生披针形效应，用于基本的导向。同时，微毛具有双重功能：构建自湿润的超亲水表面以提高水的传输速度，并使水在相反方向扩散以实现自主重新分配。我们通过理论分析和有限元模拟来解释这种多尺度传输行为。我们的研究结果展示了跨尺度地形如何共同作用于高效的自主流体操控，具有诸如液滴驱动、雾收集和海水淡化等潜在应用，为提高液体处理效率和降低能耗提供了途径。
