Department of Photonics, National Cheng Kung University, Tainan, 701, Taiwan.
Department of Opto-Electronic Engineering, National Dong Hwa University, Hualien, 974, Taiwan.
Macromol Rapid Commun. 2022 Mar;43(5):e2100736. doi: 10.1002/marc.202100736. Epub 2021 Dec 5.
Nano- and microscale morphology endows surfaces that play conspicuous roles in natural or artificial objects with unique functions. Surfaces with dynamic regulating features capable of switching the structures, patterns, and even dimensions of their surface profiles can control friction and wettability, thus having potential applications in antibacterial, haptics, and fluid dynamics. Here, a freestanding film with light-switchable surface based on cholesteric liquid crystal networks is presented to translate 2D flat plane into a 3D nanometer-scale topography. The wettability of the interface can be controlled by hiding or revealing the geometrical features of the surfaces with light. This reversible dynamic actuation is obtained through the order parameter change of the periodic cholesteric organization under a photoalignment procedure and lithography-free mode. Complex tailored structures can be used to encrypt tactile information and improve wettability by predesigning the orientation distribution of liquid crystal director. This rapid switching nanoprecision smart surface provides a novel platform for artificial skin, optics, and functional coatings.
纳米和微观形貌赋予了在自然或人工物体中起显著作用的表面独特的功能。具有能够切换结构、图案甚至表面轮廓尺寸的动态调节特征的表面可以控制摩擦和润湿性，因此在抗菌、触觉和流体动力学等领域具有潜在的应用。在这里，提出了一种基于胆甾相液晶网络的光控可切换表面的独立膜，将二维平面转化为三维纳米尺度形貌。通过光取向和无光刻模式下的周期性胆甾相组织的有序参数变化，可以用光来隐藏或揭示表面的几何特征来控制界面的润湿性。这种可逆的动态致动是通过光取向和无光刻模式下的周期性胆甾相组织的有序参数变化来实现的。通过预设计液晶指向矢的取向分布，可以使用复杂的定制结构来加密触觉信息并提高润湿性。这种快速切换的纳米精度智能表面为人工皮肤、光学和功能涂层提供了一个新的平台。
