Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.
Kent State University, Liquid Crystal Institute, Kent OH, United States.
Sci Rep. 2017 Mar 28;7:45370. doi: 10.1038/srep45370.
Various experimental and theoretical studies demonstrate that complex stimulus-responsive out-of-plane distortions such as twist of different chirality, emergence of cones, simple and anticlastic bending can be engineered and pre-programmed in a liquid crystalline rubbery material given a well-controlled director microstructure. Via 3-d finite element simulation studies, we demonstrate director-encoded chiral shape actuation in thin-film nematic polymer networks under external stimulus. Furthermore, we design two complex director fields with twisted nematic domains and nematic disclinations that encode a pattern of folds for an auto-origami box. This actuator will be flat at a reference nematic state and form four well-controlled bend distortions as orientational order changes. Device fabrication is applicable via current experimental techniques. These results are in qualitative agreement with theoretical predictions, provide insight into experimental observations, and demonstrate the value of finite element methods at the continuum level for designing and engineering liquid crystal polymeric devices.
各种实验和理论研究表明，在具有良好控制的指向矢微结构的液晶橡胶状材料中，可以设计和预先编程各种复杂的对外界刺激有响应的面外扭曲，如不同手性的扭曲、锥的出现、简单和反向弯曲。通过 3-d 有限元模拟研究，我们在外力刺激下展示了薄膜向列聚合物网络中由指向矢编码的手性形状致动。此外，我们设计了两个具有扭曲向列畴和向列位错的复杂指向矢场，为自折纸盒编码折叠图案。该致动器在参考向列态时为平面，并在取向序变化时形成四个可控制的弯曲变形。通过当前的实验技术可以实现器件制造。这些结果与理论预测定性一致，为实验观察提供了深入了解，并展示了有限元方法在连续体水平上设计和工程液晶聚合物器件的价值。
