News and Reviews (Januar 2018)

Dreidimensionale Sicherheitsmerkmale

Security through 3D-printed microstructures

3D printed safety features_KIT.jpg

Three-dimensional fluorescent safety features. (a) 3D reconstruction from slices with a confocal fluorescence laser microscope. (b) Individual z-slices of the structure in (a) for different structure depths z. (F. Mayer, M. Wegener, Karlsruhe Institute for Technology)

Researchers from the group of Prof. Dr. Martin Wegener at Karlsruhe Institute of Technology (KIT) and the company ZEISS have successfully printed fluorescent 3D structures by means of Nanoscribe’s Photonic Professional GT. They produced fluorescent microstructures with approximately 100 micrometers length from a total of three materials: one nonfluorescent and two fluorescent photoresists (see image). Specifically, semiconductor quantum dots that fluoresce in different colors were printed onto the non-fluorescent 3D cross-grid scaffold. This way, fluorescent markers can be arranged freely in all three dimensions. Hence, one single security structure enables many test images to be created one above the other within the structure. Each image can then be read out layer by layer using a confocal fluorescence laser scanning microscope. Thus, these security features are not only individually structured, but also very complex in their fabrication, making it difficult for counterfeiters to copy them.

Read more in the publication: 3D Fluorescence-Based Security Features by 3D Laser Lithography