Programming structural-colour modulation range of elastomer enables information storage

Abstract

ABSTRACT Cholesteric liquid crystal elastomers (CLCEs) has garnered significant attention in the field of information display and storage. Obtaining multiple structural colours in a single elastomer film is highly desirable but presents a considerable challenge. Here, we have successfully achieved manipulable range of structural colours in a CLCE film by ingeniously introducing the photopolymerisation during thiol-acrylate reaction process. This particular strategy involves triggering spatial shrinkage of the polymer network in a pre-designed region following solvent evaporation, resulting in a blue shift of the structural colour compared to the background. Consequently, we can construct multi-colour and multi-pattern elastomer films by precisely controlling the localised polymerisation. Notably, these patterns can be concealed in a reversible manner as the film undergoes a specific degree of elongation and can be restored when external force is removed. This work demonstrates a straightforward method of programming structural-colour modulation range, eliminating the need for material changes or intricate preparation processes, broadening the applications of stretchable elastomers in information storage, encryption, anti-counterfeiting, and dynamic photonics.