Droplet Manipulation: Magically Cut Apart Microdroplet by Smart Nanofibrils Wire
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.