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Updated: Jan 22, 2026

High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
Published on: October 31, 2019
Flow-driven disclination lines of nematic liquid crystals inside a rectangular microchannel
Zongdai Liu1, Dan Luo2, Kun-Lin Yang3
1Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117576, Singapore. cheyk@nus.edu.sg and Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Xueyuan Road 1088, Shenzhen, Guangdong 518055, China. luod@sustech.edu.cn.
Abstract:
For nematic liquid crystals (LCs), a disclination line is formed when the director of the LCs changes abruptly. In this study, we demonstrate an approach to form dynamic disclination lines by flowing the nematic liquid crystal 4-cyano-4'-pentylbiphenyl (5CB) in rectangular microchannels with a large aspect ratio. The dynamic disclination line moves gradually from the side toward the centre of the microchannel when the Ericksen number reaches 8.5. At the critical Ericksen number, influence of the anchoring energy on the side wall extends to the centre of the microchannel and determines the final position of the dynamic disclination line. As a result, the orientation of the LC is influenced by surface defects of the side wall. This phenomenon can be used to detect minute surface defects on the side wall and is potentially useful for visual sensing applications that require high sensitivity.
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