ALEXANDRIA, Va., June 12 -- United States Patent no. 12,296,391, issued on May 13, was assigned to BASF SE (Ludwigshafen am Rhein, Germany).

"Security element" was invented by Nikolay A. Grigorenko (Basel, Switzerland) and Michelle Richert (Basel, Switzerland).

According to the abstract* released by the U.S. Patent & Trademark Office: "The present invention relates to security elements, comprising (a) a substrate, (b) on at least part of the substrate surface a metal layer, (c) optionally on at least part of the metal layer a dielectric layer, (d) on at least part of the metal layer, or the dielectric layer, a layer obtained by overcoating the metal layer, or the dielectric layer with a composition, comprising (i) silver nanoparticles, (i...