Printing Convertible Microstructures into Elastomer Matrix for Multiliquids Adaptive Information Encryption

Abstract Adaptive optical performance based on convertible microstructures is very useful for information encryption. However, the facile patterning of microstructures in reliable manner and the unclonable coding are still major challenges. The direct 3D printing of water droplets is reported as templates to polydimethylsiloxane (PDMS) precursor, followed by water evaporation in curing, which introduces convertible microcrease in the elastomeric matrix. The samples show optical response to liquids with the conversion of inner creases to ponds or cavities. The stochastic array of the resulted microstructures ensures the unclonability of the codes. Water‐responsive fluorescence emission is observed when a hydrosoluble dye is added to the microstructures, further enhancing the encryption safe level. Besides, the high stability of the PDMS matrix to ultraviolet irradiation and extreme temperature environment endows the material large application potentials in varied fields. This research provides a potential solution for facile, tough, and fundamentally safe information encryption.