CounterfeitInvisible inks to help foil counterfeiters

Published 15 May 2015

Counterfeiting is very big business worldwide, with $650 billion per year lost globally, according to the International Chamber of Commerce. Scientists have invented sophisticated fluorescent inks that one day could be used as multicolored barcodes for consumers to authenticate products that are often counterfeited. Snap a photo with your smartphone, and it will tell you if the item is real and worth your money.

Real or counterfeit? Northwestern University scientists have invented sophisticated fluorescent inks that one day could be used as multicolored barcodes for consumers to authenticate products that are often counterfeited. Snap a photo with your smartphone, and it will tell you if the item is real and worth your money.

Counterfeiting is very big business worldwide, with $650 billion per year lost globally, according to the International Chamber of Commerce. The new fluorescent inks give manufacturers and consumers an authentication tool that would be very difficult for counterfeiters to mimic.

These inks, which can be printed using an inkjet printer, are invisible under normal light but visible under ultraviolet light. The inks could be stamped as barcodes or QR codes on anything from banknotes and bottles of whisky to luxury handbags and expensive cosmetics, providing proof of authenticity.

An NU release reports that a key advantage is the control one has over the color of the ink; the inks can be made in single colors or as multicolor gradients. An ink’s color depends on the amounts and interaction of three different “ingredient” molecules, providing a built-in “molecular encryption” tool. (One of the ingredients is a sugar.) Even a tiny tweak to the ink’s composition results in a significant color change.

“We have introduced a level of complexity not seen before in tools to combat counterfeiters,” said Sir Fraser Stoddart, the senior author of the study. “Our inks are similar to the proprietary formulations of soft drinks. One could approximate their flavor using other ingredients, but it would be impossible to match the flavor exactly without a precise knowledge of the recipe.”

Sir Fraser is the Board of Trustees Professor of Chemistry in the Weinberg College of Arts and Sciences.

“The rather unusual relationship between the composition of the inks and their color makes them ideal for security applications where it’s desirable to keep certain information encrypted or to have brand items with unique labels that can be authenticated easily,” Stoddart said.

With a manufacturer controlling the ink’s “recipe,” or chemical composition, counterfeiters would find it virtually impossible to reverse engineer the color information encoded in the printed barcodes, QR codes or trademarks. Even the inks’ inventors would not be able to reverse engineer the process without a detailed knowledge of the encryption settings.