Programmable and Flexible Fluorochromic Polymer Microarrays for Information Storage

Photoresponsive fluorochromic materials are regarded as an effective means for information storage. Their reversible changes of color and fluorescence facilitate the storage process and increase the possible storage capacity. Here, we propose an optically reconfigurable Förster resonance energy transfer (FRET) process to realize tunable emissions based on photochromic spiropyrans and common fluorophores. The kinetics of the photoisomerization of the spiropyran and the FRET process of the composite were systematically investigated. Through tuning the ratios of the acceptor spiropyran and donor fluorophore and external light stimuli, a programmable FRET process was developed to obtain tunable outputs. More importantly, flexible microarrays were fabricated from such fluorochromic mixtures by inkjet printing (230 ppi) and the dynamic FRET process could also be applied to generate tunable fluorescence in ready-made microstructures. The flexible patterns created using the microarrays could be used as novel optically readable media for information storage by altering the composition and optical performance of every feature within the microarray. A key aspect of information storage such is anti-counterfeiting, and these colorful displays can be fabricated and integrated in a simple and straightforward system. The reliable fabrication and programmable optical performances of these large-scale flexible polymer microarrays represent a substantial step toward high-density and high-security information storage platforms.