Title: Directed Pinning of Moving Water Droplets on Photoresponsive Liquid Crystal Mats

Author: Yuyun Liu, Chongyu Zhu, Yong Zhao, Xin Qing, Feng Wang, Daosheng Deng, Jia Wei, Yanlei Yu*

Journal: Adv. Mater. Interfaces 2019, 6(21), 1901158

Abstract:

Compared to conventional continuous-flow liquid manipulation, the direct control of liquid droplets on an open surface prevents the potential cross contamination during liquid transfer, which is advantageous for biological microliquids. However, the fabrication techniques of smart surfaces and the fast manipulation of droplets remotely remain difficult, limiting its practical application. Herein, large-scaled photoresponsive superhydrophobic mats fabricated by the electrospinning of linear liquid crystal polymer are presented. Upon the alternated irradiation of UV-vis light, these mats exhibit significant, fast, and reversible change of adhesion, while their surfaces maintain the superhydrophobicity. Therefore, the water droplets can be pinned at any directed point on the mat surface after the fast superhydrophobic adhesion switch by the remote control of light. It is expected that the active manipulation of discrete droplets on an open surface through these photoresponsive mats provides a new concept for microdroplet manipulation,allowing for minimal reactions among biological samples.

论文链接：https://onlinelibrary.wiley.com/doi/full/10.1002/admi.201901158

PDF下载：Directed Pinning of Moving Water Droplets on Photoresponsive Liquid Crystal Mats.pdf

从高分子量的光响应LLCP出发，本文通过静电纺丝法制备了大尺度的光响应超疏水垫，并展示了疏水垫在光控下的超疏水粘附状态的快速切换。由于纳米纤维表面偶氮苯介晶的光致异构化，引起其极性变化和重新取向，导致垫子上粘附力（AF）和表面自由能发生快速、巨大变化。基于这种独特的光响应特性，这些垫子允许在紫外线照射2秒后将水滴固定在表面上的任何定向点。该光响应LLCP超疏水垫有望成为在开放表面上对离散液滴进行主动操作的理想候选者，将进一步扩展用于诊断和药物筛选的最小生物反应。