Programming liquid crystal elastomers for multistep ambidirectional deformability

Ambidirectionality, which is the ability of structural elements to move beyond a reference state in two opposite directions, is common in nature. However, conventional soft materials are typically limited to a single, unidirectional deformation unless complex hybrid constructs are used. We exploited the combination of mesogen self-assembly, polymer chain elasticity, and polymerization-induced stress to design liquid crystalline elastomers that exhibit two mesophases: chevron smectic C (cSmC) and smectic A (SmA). Inducing the cSmC-SmA–isotropic phase transition led to an unusual inversion of the strain field in the microstructure, resulting in opposite deformation modes (e.g., consecutive shrinkage or expansion and right-handed or left-handed twisting and tilting in opposite directions) and high-frequency nonmonotonic oscillations. Further, this ambidirectional movement is scalable and can be used to generate Gaussian transformations at the macroscale.. Authors: Yao, Yuxing [Harvard Univ., Cambridge, MA (United States); Hong Kong University of Science and Technology (HKUST) (Hong Kong)] (ORCID:0000000303376372); Wilborn, Atalaya Milan [Harvard Univ., Cambridge, MA (United States)] (ORCID:0009000906184967); Lemaire, Baptiste [Harvard Univ., Cambridge, MA (United States)] (ORCID:0000000267491081); Trigka, Foteini [Univ. of Groningen (Netherlands)] (ORCID:0000000173771525); Stricker, Friedrich [Harvard Univ., Cambridge, MA (United States)] (ORCID:0000000273246840). DOE Contract: SC0005247; SC0012704. Subjects: 36 MATERIALS SCIENCE