Most of today's anti-counterfeiting labels have one thing in common: they're visible, meaning that counterfeiters can attempt to replicate their appearance. An experimental new sticker, however, contains "invisible" imagery.
Being developed by scientists at Russia's ITMO University and St. Petersburg Academic University, the label takes the form of a thin, flexible silicon-based film. The surface of that film is filled with a "lattice" of tiny holes, some of which contain the rare earth element erbium, others of which don't.
When a system-specific scanner is used to irradiate the sticker with laser light, the erbium within the select holes luminesces in a distinct color, creating a now-visible pattern. That pattern can then be checked against one that's been officially assigned by the product's manufacturer.
The label reportedly stands up well to both mechanical and chemical effects. And as an added layer of security, it's also possible to measure the intensity, wavelength, and radiative lifetime of the luminescence, which can likewise be compared to manufacturer data on file.
A paper on the research was recently published in the journal Advanced Materials.
Source: ITMO University
