writer：Shaomin Wang, L. Zhu, D. Yu, X. Han, L. Zhong, Y. Hou, Yongmei Zheng*
keywords：Water collection
source：期刊
Issue time：2023年

Helical structure is ubiquitous in nature with high-order configuration,

specific paths, large superficial areas, providing an approach to bioinspired

wettability control. Owing to its special hydrophilic rough surfaces and

periodic knot and joint structure, natural spider silk can catch tiny droplets in

fog and transport them directionally, sparking scientific interest in bioinspired

knotted microfibers to address the risk of water scarcity. To further enhance

the water collection ability, a bioinspired helical-groove-modified spindle-knot

(HSK) microfiber is continuously fabricated in this work by a simple coating

method combined with crack regulation. The formation and morphology can

be precisely manipulated by adjusting the drawing velocity and concentration

of the coating solution. Compared with smooth spindle-knot microfibers, HSK

exhibits greater performances of wetting speed, droplets growth rate, and

hanging ability, which can be attributed to the unique helical paths that bring

capillary force difference and offer extra three-phase contact line lengths for

water collection behavior. The maximum droplet volume is almost 2114 times

that of the microfiber knots, which is the highest compared with previous

reports. Moreover, HSK microfibers are endowed with repairable wettability,

long-term durability, excellent mechanical properties, and flexibility, showing

great potential in the realm of applications for large-scale water collection.

https://doi.org/10.1002/adfm.202305244