Invisible QR Codes Tackle Counterfeit Bank Notes and Other Security Applications

The QR code is made of tiny nanoparticles that have been combined with blue and green fluorescence ink, which is invisible until illuminated with laser light. It is generated using computer-aided design (CAD) and printed onto a surface using an aerosol jet printer.

According to the researchers, the QR code will add an increased level of security over existing counterfeiting methods as the complexity of the production process makes it very difficult to replicate.