A Dual‐Responsive Liquid Crystal Elastomer for Multi‐Level Encryption and Transient Information Display

Abstract

Information security has gained increasing attention in the past decade, leading to the development of advanced materials for anti‐counterfeiting, encryption and instantaneous information display. However, it remains challenging to achieve high information security with simple encryption procedures and low‐energy stimuli. Herein, a series of strain/temperature‐responsive liquid crystal elastomers (LCEs) are developed to achieve dual‐modal, multi‐level information encryption and real‐time, rewritable transient information display. The as‐prepared polydomain LCEs can change from an opaque state to a transparent state under strain or temperature stimuli, with the transition strains or temperatures highly dependent on the concentration of long‐chain flexible spacers. Information encrypted by different LCE inks can be decrypted under specific strains or temperatures, leading to multi‐level protection of information security. Furthermore, with the combination of the phase transition of polydomain LCEs and the photothermal effect of multi‐walled carbon nanotubes (MWCNTs), we achieved a repeatable transient information display by using near‐infrared (NIR) light as a pen for writing. This study provides new insight into the development of advanced encryption materials with versatility and high security for broad applications.