posted on 2022-12-16, 15:35authored byRuijie Wang, Fan Jin, Yufen Li, Xiaoyan Yu, Hua Lai, Yuyan Liu, Zhongjun Cheng
Recently,
research about controllable droplet transportation in
tubes has aroused increased interest. However, existing strategies
mainly depend on the elastic tube’s shape variation that needs
constant external stimuli. Meanwhile, these reported tubes are only
suitable for wetting liquids. To achieve the transportation of diverse
liquids, different coatings are needed to modify the tube’s
inner surface to realize complete wetting of different liquids. Herein,
we advance a design principle by combining a shape memory polymer
(SMP) tube and Nepenthes pitcher plant-inspired
slippery surface, which can solve the above-mentioned problems. The
SMP offers a tunable tube shape owing to its shape memory effect (SME);
the slippery surface reduces the adhesion and expands the applicable
range of liquids. Transportation of both water and oils in a wide
range of surface tension values can be smartly controlled. The results
show that not only the transportation speed and direction can be adjusted
but also diverse modes including round-trip transportation, segmented
transportation, and antigravity transportation can be achieved. Moreover,
applications of the tube in batch inspection of different droplets
and step-by-step control of multiple microreactions are also displayed.
This work reports a strategy for droplet transportation control based
on the tube’s SME, which initiates some fresh ideas for designing
new superwetting materials toward smart liquid transportation.