Light-Controlled Dynamic Gradient Helical Superstructure in Photo-Responsive Polymer-Dispersed Cholesteric Liquid Crystals for Triple-Lock Optical Encryption.

Beyond conventional static strategies, achieving dynamic structural color information encoding using photo-responsive cholesteric liquid crystals (pCLCs) for secure and multifunctional encryption remains a grand challenge. Here, the light-controlled dynamic gradient helical superstructure is introduced in a photo-responsive polymer-dispersed cholesteric liquid crystal (pPDCLC) system by exploiting the intrinsic light attenuation effect, enabling tunable structural color evolution for dynamic encryption materials. Specifically, the light attenuation effect induces depth-dependent photo-isomerization of chiral dopants, generating a dynamic pitch gradient and the corresponding structural color evolution. By regulating the extent of the light attenuation effect, the evolution rates of structural color in pPDCLCs can be controlled. Furthermore, this tunable structural color evolution can be extended to other pCLCs, demonstrating the generality of the light-controlled process in pCLC systems. As a result, time-resolved anti-counterfeiting patterns and time-temperature-color triple-lock information encryption are achieved. Crucially, this dynamic encryption strategy is further developed as a proof-of-concept time-temperature indicator capable of recording thermal history and indicating suitable usage temperatures under laboratory conditions. This work establishes a dynamic structural color platform that enables photo-responsive process encoding, providing a new paradigm for robust and secure pCLC-based encryption.