Squeezing a drop of nematic liquid crystal with strong elasticity effects
Squeezing a drop of nematic liquid crystal with strong elasticity effects
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DOI：
10.1063/1.5110878
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发表时间：
2019-08-01
影响因子：
4.6
通讯作者：
Weegels, L.
中科院分区：
文献类型：
--
作者：
Cousins, J. R. L.;Wilson, S. K.;Weegels, L.
一滴填充（ODF）方法广泛用于液晶器件的工业制造。出于需要一个更好的基本理解的分子的重新取向，由于在这种制造方法中的液晶的流动，我们制定和分析的ODF方法的挤压膜模型。具体地说，我们考虑了一个渐近制度，其中液滴是薄的，惯性效应是弱的，弹性效应是强的四个特定的锚定情况下，在顶板和基板的挤压膜（即，平面、垂面、混合对齐的双折射和π-单元无限锚定条件）和顶板运动的两种不同情况（即，规定速度和规定力）。的领导和一阶导演角，径向速度，垂直速度和压力的解析表达式。剪切和耦合应力在顶板和基板上的计算和解释的影响，流动可能会有在板上的分子的对齐，可能导致虚假的光学缺陷（“mura”）的形成。由AIP Publishing授权出版。
The One Drop Filling (ODF) method is widely used for the industrial manufacture of liquid crystal devices. Motivated by the need for a better fundamental understanding of the reorientation of the molecules due to the flow of the liquid crystal during this manufacturing method, we formulate and analyze a squeeze-film model for the ODF method. Specifically, we consider a nematic squeeze film in the asymptotic regime in which the drop is thin, inertial effects are weak, and elasticity effects are strong for four specific anchoring cases at the top plate and the substrate (namely, planar, homeotropic, hybrid aligned nematic, and pi-cell infinite anchoring conditions) and for two different scenarios for the motion of the top plate (namely, prescribed speed and prescribed force). Analytical expressions for the leading- and first-order director angles, radial velocity, vertical velocity, and pressure are obtained. Shear and couple stresses at the top plate and the substrate are calculated and are interpreted in terms of the effect that flow may have on the alignment of the molecules at the plates, potentially leading to the formation of spurious optical defects ("mura"). Published under license by AIP Publishing.