Invisible tags: Physicists at TU Dresden write, read and erase with the use of light

A team of physicists headed by Prof. Sebastian Reineke of TU Dresden developed a new kind of storing information in fully transparent plastic foils. Their innovative idea is now published in the renowned online journal “Science Advances”.

Prof. Reineke and his LEXOS team work with simple plastic foils with a thickness of less than 50 µm, which is thinner than a human hair. In these transparent plastic foils, they introduced organic luminescent molecules. In the beginning, these molecules are in an inactive, dark state. Using ultraviolet irradiation, it is possible to turn this dark state locally into an active, luminescent one. By mask illumination or laser writing, activated patterns can be printed into the foil having a resolution comparable to common laser printers. Similar to glow-in-the-dark stickers, the patterns can be brought to shine and the imprinted information can be read out. By illuminating with infrared light, the tag is erased completely and new data can be written into it.