中国科学技术大学学报 ›› 2019, Vol. 49 ›› Issue (3): 231-236.DOI: 10.3969/j.issn.0253-2778.2019.03.008

• 原创论文 • 上一篇    下一篇

局部光照下玻璃态液晶薄膜的非线性变形形貌

成星宇   

  1. 中国科学技术大学近代力学系, 安徽合肥 230026
  • 收稿日期:2018-10-10 修回日期:2018-11-16 出版日期:2019-03-30 发布日期:2019-03-30
  • 作者简介:成星宇,男,1990年生,硕士. 研究方向:向列型液晶薄膜的光致变形. E-mail:cxywawa@mail.ustc.edu.cn
  • 基金资助:
    国家自然科学基金(11572308)资助.

Nonlinear deformation topography of glassy nematic films under local illumination

CHENG Xingyu   

  1. Department of Modern Mechanics, University of Science and Technology of China, Hefei 230026, China
  • Received:2018-10-10 Revised:2018-11-16 Online:2019-03-30 Published:2019-03-30

摘要: 含偶氮苯分子的玻璃态液晶薄膜的光响应特性使其在光驱动变形器件方面具有重要应用前景. 基于Fppl-von Kármán板理论和动力学方法发展了一种预言局部光照下玻璃态液晶薄膜非线性变形形貌的数值方法,并针对伸展型及扭曲型两种典型指向矢分布给出了入射光斑为圆形时的详细计算结果. 研究表明,当光斑半径与薄膜厚度比增大至一定的临界值,薄膜感光部分的形貌发生急剧变化,伴随着Gauss曲率由负到正的转变. 这一现象归因于入射光强沿膜厚方向衰减导致的自发弯矩,可望应用于新型非接触调控式变形器件的设计.

关键词: 玻璃态液晶薄膜, 光致变形, 局部光照

Abstract: Azobenzene-containing nematic glasses have an attractive application perspective in photo-driven deformation devices due to their unique photo-responsive properties. Based on the Fppl-von Kármán plate theory and a kinetics method, a numerical approach was developed to predict the nonlinear deformation topography of glassy nematic films under local illumination, and detailed results were given for two typical director fields of splay-bend and twist distributions when the spot of incident light is a circle. It is found that when the ratio of spot radius to film thickness is increased to a certain critical value, dramatic variation of the topography of the exposed part of the film occurs, accompanying the transition of Gauss curvature from positive to negative. This phenomenon is attributed to the spontaneous bending moments induced by attenuation of light intensity across film thickness, and may be applied to design new types of deformation devices with contactless control.

Key words: glassy nematic film, photo-induced deformation, local illumination