team of researchers from Western University has developed a promising new approach that offers multiple levels of anticounterfeiting protection, making identifying markings that much harder to forge. The technology they’ve developed uses materials with a property called persistent luminescence (PersL).
The luminescent materials currently in use for anticounterfeiting become visible when exposed to UV light, but stop glowing when the light source is removed. The new materials created by the Western team – using the Canadian Light Source (CLS) at the University of Saskatchewan (USask) – are inorganic phosphor nanoparticles that remain visible to the human eye for several minutes after UV light is turned off. They also give off a shade of red light that’s not easily reproduced. And most significantly – an identification mark can be “programmed” to disappear in stages, with some elements vanishing almost immediately, while other elements fade away over several minutes.
“We can incorporate dopants into our material to construct a complicated pattern so that different parts glow for different durations,” says Dr. Lijia Liu, a professor in Western’s Department of Chemistry. “That is our ultimate security. It will be very difficult to find something that can achieve that property.”