The next generation of QR codes have been created by researchers at the South Dakota School of Mines and Technology – and theyre invisible to the naked eye.

These invisible QR codes could be used to authenticate banknotes, and to help combat the piracy expected to follow the advent of 3D printing, while ensuring that the exterior of the object does not have any visible security markings. 

The QR codes are created from nanoparticles of blue and green fluorescent ink. They can be seen under near-infrared laser light and a smartphone can be used to take a picture which is scanned as usual.

“We can take the level of security from covert to forensic by simply adding a microscopic message in the QR code, in a different coloured upconverting ink, which then requires a microscope to read the upconverted QR code,” said Jeevan Meruga, the lead author of the study, which appeared in the British journal Nanotechnology.

The codes were simply created using an online QR code generator, before converting them for aerosol jet printing, a process that currently takes more than an hour – but that could be cut significantly if the practice becomes mainstream. 

Join us at Mobile Marketing Live, our new two-day conference, exhibition and networking event being held at Londons Business Design Centre on 1-2 October