The barcodes have been created in order to be viewed only when shown under infrared light.
University of South Dakota professor Stanley May, along with Jon Kellar, both from the School of Mines and Technology, have created QR codes that become visible only when they are displayed under an infrared light.
The researchers from the university have created the barcode in order to help prevent counterfeiting.
They are hoping that by adding these invisible QR codes to official documents, it might help to provide easier recognition of forgeries and counterfeits and make it more difficult for criminals to be able to produce convincing fakes. May has used nanoparticle technology over the last few years in order to develop a clear ink solvent into which it has been integrated. He has been working with Kellar as well as William Cross in order to make the ink printable.
The team has now been able to print QR codes through the use of this ink and a special printer.
The printing requires a special aerosol lab printer, but it is capable of creating basic shapes and letters on paper and certain objects. The researchers then took things a step further by creating a way to print QR codes that were invisible to the naked eye. The concept was first thought of and tested by graduate student Jeevan Meruga, who was working with Kellar.
According to Kellar, Meruga “came to me one day and said ‘Jon, look what I printed,’”. He explained that “I didn’t even know what it was at first, but then I quickly figured out what it was and how important this could be.”
When the QR codes were printed in the clear solution, they can be added to virtually any surface and remain completely invisible to the naked eye until infrared light is added. Only then does it become visible. This way, it could make it challenging to fraudulently replicate official documents or currency, for instance.
It has also been suggested that the invisible QR codes could be added to identification such as drivers licenses and others that need to be very difficult to forge.