Low-grade wind-driven directional flow in anchored droplets

作者：Shan Peng, Binglin Xie, Yanlei Wang, Mi Wang, Xiaoxin Chen, Xiaoyu Ji, Chenyang Zhao, Gang Lü, Dianyu Wang, Ruiran Hao, Mingzhan Wang, Nan Hu, Hongyan He, Yulong Ding, Shuang Zheng · 发表于：Proceedings of the National Academy of Sciences · 年份：2023 · DOI：10.1073/pnas.2303466120 · 被引用次数：15 · 研究领域：Surface Modification and Superhydrophobicity、Icing and De-icing Technologies、Advanced Sensor and Energy Harvesting Materials

Low-grade wind with airspeed V wind < 5 m/s, while distributed far more abundantly, is still challenging to extract because current turbine-based technologies require particular geography (e.g., wide-open land or off-shore regions) with year-round V wind > 5 m/s to effectively rotate the blades. Here, we report that low-speed airflow can sensitively enable directional flow within nanowire-anchored ionic liquid (IL) drops. Specifically, wind-induced air/liquid friction continuously raises directional leeward fluid transport in the upper portion, whereas three-phase contact line (TCL) pinning blocks further movement of IL. To remove excessive accumulation of IL near TCL, fluid dives, and headwind flow forms in the lower portion, as confirmed by microscope observation. Such stratified circulating flow within single drop can generate voltage output up to ~0.84 V, which we further scale up to ~60 V using drop “wind farms”. Our results demonstrate a technology to tap the widespread low-grade wind as a reliable energy resource.