Colour-Changing Smart Materials for Rapid Authentication

At the recent High Security Printing™ EMEA conference in Basel, Switzerland, Dr Alexander Brannan from the University of Manchester, and Gary Spinks of Security Fibres UK, presented advances in colour-changing smart materials designed for rapid authentication. This technology addresses key issues in anticounterfeiting by integrating academic research with industrial application.

Traditional fluorescent pigments are an essential tool in security printing. However, the increasing availability of cheap substitutes means that these pigments are now much easier to simulate, significantly limiting their effectiveness and making them vulnerable to counterfeiting. This growing challenge highlights the need for more robust and sophisticated authentication solutions.

The smart materials developed by Dr Brannan and Spinks offer a solution through advanced light-emitting compounds. Their key innovation lies in a single molecule capable of exhibiting two distinct photoluminescent behaviours: fluorescence, which produces an immediate glow, and phosphorescence, where light emission continues after the excitation source is removed. As Dr Brannan puts it: ‘this is not a mixture of compounds. In a single molecule you get a fast fluorescence, followed by phosphorescence’.