writer：Miaoxin Zhang, Jinghui Li, Wenlei Pei, Yufang Liu, Lieshuang Zhong, Shaomin Wang, and Yongmei Zheng
keywords：Manipulation of droplets
source：期刊
specific source：Adv. Mater. Interfaces 2020, 7, 2000161
Issue time：2020年

A strategy of droplet manipulation is introduced, that is, an ethanol-wetted

nanofibrils wire (ENW) that can smartly generate a repellent force to cut

apart a spreading water droplet to split droplets (SDs) on a superhydrophilic

surface without any contact. The repellent force is attributed to a unique

Marangoni state inside droplet due to the interaction between vapor–liquid

interfaces, along with the gradient surface tension formed between the

ENW and spreading droplet. It is demonstrated that such an ENW makes

an as-spreading water droplet with volume of 5–25 μL to be accurately

cut apart into tiny SDs in various proportions (e.g., 1/9–1/1) without loss,

and the minimum SD can be 1.7 μL in volume. A spreading droplet can be

one-step cut apart into patterns and further some micro-reactors can be

achieved by using ENW manipulations, respectively. This finding offers

insights into the design of novel droplet-manipulating materials that can be

extended into microfluidics, microreactors, and others.