Bacteriorhodopsin-based Multi-level Optical Security Features

摘要

Bacteriorhodopsin (BR) is a crystalline photochromic protein which shows an astonishing stability towards chemical and thermal degradation. This material is used in a variety of applications which have been developed, among them photochromic color-changes, optical data storage and molecular traceability of the material. Integration of all three security levels in a document will be shown. One year lasting field tests have proven the stability of the system in daily use. First applications of polarization encoded data storage and data encryption have been realized successfully. The development of BR-based security features will be reviewed and newer developments will be presented, among them individualized computer generated holograms and the development of ink-jet inks. The data-storage capabilities of the biomaterial BR have been further developed and now visual detectable as well as visual non-detectable storage processes are available. The molecular mechanisms of the data storage process will be presented.