To
fight the boom in counterfeiting and especially the fraud of official
documents, we propose herein original multilevel integrated security
features: photoluminescent nanoparticle-based tags (PL tags). Using
the electrical microcontact printing technique, PL tags are fabricated
at large scale and are successfully integrated in the production line
of plastic cards. We introduce COC-based stamps in the fabrication
process to meet industrial constraints in terms of speed, cost and
robustness. Depending on the resolution of security features, from
several millimeters down to several micrometers, PL tags can also
combine several degrees of reading and so security. Indeed, using
a simple blue LED, they could be quickly identifiable by naked eye
or a simple smartphone camera. In addition, they could also embed
smaller features only readable with an optical microscope.
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