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USD professor develops invisible QR codes

University of South Dakota professor Stanley May, along with researchers and engineers from the South Dakota School of Mines and Technology, have developed an “invisible” Quick Response code.

They are hoping the new technology can help combat security counterfeiting and forgery.

Over the past few years, May, who developed a clear ink solvent integrated with nanoparticle technology, worked with SDSM&T professors Jon Kellar and William Cross on making the ink printable.

With the help of graduate researchers at SDSM&T, Kellar and Cross were able to begin printing, with a special aerosol lab printer, basic letters and shapes onto various objects including paper.

One day, Jeevan Meruga, a graduate student researching with Kellar, decided to use the technology to print a QR code. When Meruga approached Kellar of his findings, Kellar didn’t know what to make of it.

“[Meruga] came to me one day and said ‘Jon, look what I printed,’” said Kellar. “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.”

The QR code is a square two-dimensional box filled with various smaller black and white blocks. Typically companies use these codes for product marketing and can be readily scanned by smart phones. Upon scanning users are then taken to another source to be given more information on the product.

When the clear solution is printed on any surface ,it appears invisible to the naked eye and can only be seen under infrared lighting.

“When printed on white paper it just looks like a white piece of paper, nothing there,” said May. “The human eye can only process visible light, so in order to view the covert code you’d need infrared lighting.”

As current QR codes are able to store vast amounts of information, the invisible ones could be used to for the same purpose. Storing a quantity of information that cannot be seen by the naked eye is one way to keep unwanted viewers from seeing it. Information that isn’t supposed to be seen by anyone else such as classified documents can be kept a secret.

Another proposed usage of these covert codes is combating against counterfeiting and forgery, as a majority of companies trying to obtain the rights to the technology are looking to use it for just that, said May.

According to May, items such as driver’s licenses, passports and social security cards that are widely forged would become more difficult to reproduce.

“The ink uses nanotechnology which won’t be easy to counterfeit by an ordinary person,” said May. “We can also manipulate things that are technical with the spectral signatures and color that would make it much more difficult to copy.”

According to Kellar, the technology could potentially be printed onto almost any surface, which gives it more varieties of ways to be incorporated.

“We’ve printed it on paper, glass, metal and Kapton [a film that can typically withstand extreme temperatures],” said May. “We’ve printed it on transparent tape. We’ve printed it on a ballpoint pen and on Bayer aspirin. It just shows that it can be placed on potentially any surface.”

May said the ink could even be printed on human skin, but the warmth from the infrared lighting would be unpleasant.

May and his partners are working on being able to mass print the codes using regular ink jet printers, as opposed to the aerosol lab printers, which aren’t made for mass printing.