Zhao Fang, Li Yuzhan, Gao Hong, Tao Ran, Mao Yiqi, Chen Yu, Zhou Sheng, Zhao Jianming, Wang Dong
Division of Material Engineering, China Academy of Space Technology, Beijing, 100094, P. R. China.
Department of Materials Physics and Chemistry, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, P. R. China.
Adv Sci (Weinh). 2023 Dec;10(36):e2303594. doi: 10.1002/advs.202303594. Epub 2023 Nov 9.
Deformable superstructures are man-made materials with large deformation properties that surpass those of natural materials. However, traditional deformable superstructures generally use conventional materials as substrates, limiting their applications in multi-mode reconfigurable robots and space-expandable morphing structures. In this work, amine-acrylate-based liquid crystal elastomers (LCEs) are used as deformable superstructures substrate to provide high driving stress and strain. By changing the molar ratio of amine to acrylate, the thermal and mechanical properties of the LCEs are modified. The LCE with a ratio of 0.9 exhibited improved polymerization degree, elongation at break, and toughness. Besides an anisotropic finite deformation model based on hyperelastic theory is developed for the LCEs to capture the configuration variation under temperature activation. Built upon these findings, an LCE-based paper-cutting structure with negative Poisson's ratio and a 2D lattice superstructure model are combined, processed, and molded by laser cutting. The developed superstructure is pre-programmed to the configuration required for service conditions, and the deformation processes are analyzed using both experimental and finite element methods. This study is expected to advance the application of deformable superstructures and LCEs in the fields of defense and military, aerospace, and bionic robotics.
可变形超结构是一种人造材料,具有超越天然材料的大变形特性。然而,传统的可变形超结构通常使用常规材料作为基底,限制了它们在多模式可重构机器人和空间可扩展变形结构中的应用。在这项工作中,基于胺 - 丙烯酸酯的液晶弹性体(LCEs)被用作可变形超结构的基底,以提供高驱动应力和应变。通过改变胺与丙烯酸酯的摩尔比,对LCEs的热性能和力学性能进行了改性。比例为0.9的LCE表现出更高的聚合度、断裂伸长率和韧性。此外,基于超弹性理论为LCEs建立了各向异性有限变形模型,以捕捉温度激活下的构型变化。基于这些发现,将具有负泊松比的基于LCE的剪纸结构和二维晶格超结构模型进行组合、加工,并通过激光切割成型。所开发的超结构被预编程为服务条件所需的构型,并使用实验和有限元方法对变形过程进行分析。本研究有望推动可变形超结构和LCEs在国防军事、航空航天和仿生机器人领域的应用。