Two-step crosslinked liquid-crystalline elastomer with reversible two-way shape memory characteristics

Liquid-crystalline elastomers (LCEs) possess large and equilibrium reversible anisotropic dimensional change in response to applied stimuli. The deformation behavior demonstrated by current LCE materials under the stimuli are generally determined by their own geometries and the alignment distributions of liquid crystal (LC) units in the LCE matrices. Here we report a LCE whose synthesis was through a two-stage crosslinking coupled with a mechanical reshaping process, where the shape was mechanically reset before the final crosslinking. It demonstrated reversible memory and change between the initial geometries formed during the first crosslinking stage and any reshaped geometries under the stimuli. Its deformation is not influenced by the geometries and the alignment distributions of LC units in the LCE matrix. This characteristic in LCEs holds promise in a wide range of application researches requiring sophisticated functions and smart structures.University of Wisconsin - Madison Vilas Associates Program - Vilas Trustees; Wisconsin Institutes for Discovery; U.S. National Science Foundation [ECCS 0702095]SCI(E)ARTICLE113-2265