A General Control Strategy to Micropattern Topological Defects in Nematic Liquid Crystals Using Ionically Charged Dielectric Surface
A General Control Strategy to Micropattern Topological Defects in Nematic Liquid Crystals Using Ionically Charged Dielectric Surface
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DOI：
10.1002/admi.202100379
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发表时间：
2021-05
影响因子：
5.4
通讯作者：
Y. Sasaki;Jun Takahashi;Shunsuke Yokokawa;T. Kikkawa;Ryota Mikami;H. Orihara
中科院分区：
文献类型：
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作者：
Y. Sasaki;Jun Takahashi;Shunsuke Yokokawa;T. Kikkawa;Ryota Mikami;H. Orihara
定制软材料中的自组织纳米/微米结构对于开发新兴应用的内在功能特性至关重要。液晶中的工程拓扑缺陷对于电光设备以及软执行器变形表面很有趣。尽管潜力巨大，但目前很少有自下而上的方法可以在大面积上定期定位大量缺陷。开发通过简单程序实现高通量制造的基本技术非常具有挑战性。使用紫外线/臭氧处理，本文提出了一种通用且稳健的策略来生产表面，该表面可以成为向列液晶中拓扑缺陷的自组织微图案的平台，而不管包括可聚合单体在内的化合物的化学结构如何。通过应用区域选择性表面改性可以控制微图案的形成，从而显着提高制造效率。通过低频阻抗谱，微图案形成时表观阈值电压的独特频率依赖性通过实验被分配给当电介质表面被离子添加剂充电时发生的独特的重新取向响应。这种表征为进一步设计液晶中的自组织拓扑缺陷提供了重要的指导。
Tailoring self‐organized nano/microstructures in soft materials is crucial for exploiting intrinsic functional properties toward emerging applications. Engineered topological defects in liquid crystals are interesting for electro‐optical devices as well as for soft actuators morphing surface. Despite the promising potential, there are currently few bottom‐up methods for positioning a large number of defects periodically over a large area. It is highly challenging to develop essential techniques for achieving high‐throughput fabrication with simple procedure. Using ultraviolet/ozone treatment, herein we present a general and robust strategy to produce the surface that can be a platform for a self‐organized micropattern of topological defects in nematic liquid crystals, irrespective of the chemical structure of compounds including polymerizable monomers. The micropattern formation is controllable by applying area‐selective surface modification, which dramatically improves the fabrication efficiency. By low frequency impedance spectroscopy, the distinctive frequency dependence of the apparent threshold voltage at the micropattern formation is experimentally assigned to a unique reorientational response which occurs when a dielectric surface is charged by ionic additives. This characterization provides crucial guidance in further engineering self‐organized topological defects in liquid crystals.