Stress Induced Color and Pattern for Information Coding

Abstract

AbstractOn the process of deforming polymer, its morphologies can be vividly observed and reflected via the internal stress distribution under the polarized light due to its special stretched birefringence, which gives a new way to store and read information. Inspired by this vivid character, a novel crosslinked polyurethane (PU) is designed and used as matrix for coding information, in which aluminum acetylacetonate works as the crosslinker to form dynamical crosslinked structure with coordinated bonds. By tailoring these two bonds via a region‐selective regulation, the information can be written in the crosslinked PU. Only under the polarized light, the coded information can be read as stress induced color on the deformed state. After its recovery, 2D pattern can be simultaneously formed on the surface of the film. Therefore, the information is expressed in multiple channels. Thanks to the dynamic character, the information can be also erased and rewritten. Therefore, it is a new method for information coding with a high security, which has a wide range of potential applications in data storage, anticounterfeiting labeling, information conversion, and other areas.