Fig. 1: PUF tags prepared from biobased optical ionogel films.
a One-pot preparation of the optical ionogel, respective macroscopic aspect and processing as a film to form the PUF tag. b Schematic representation of the supramolecular organisation of the optical ionogel embedding LC droplets, where LC molecules are confined inside a spheroid shell formed by imidazolium chloride IL molecules. The transversal cut of the droplet illustrates the perpendicular anchoring of the LC molecules at the surface of the droplet, promoted by the IL. c Chemical structure of the molecules of imidazolium chloride IL (CnmimCl). d Chemical structure of the LC 4-Cyano-4’-pentylbiphenyl (5CB). e Dual-step authentication pipeline, where 2 security levels must be verified for authentic tags: (i) authenticity of the static optical texture observed under polarised optical microscopy (POM); and (ii) authenticity of the dynamic POM patterns as a response to a defined organic vapour. This dual-step verification is performed by a pre-trained cloud-based AI algorithm, also enabled with the ability to detect if the tag was exposed to undue temperatures or suffered from tampering. Created in BioRender. Roque, C. (2025) https://BioRender.com/r68r365.
