Researchers at the Fraunhofer Institute for Material and Beam Technology IWS in Dresden have developed an innovative measurement technology for reliably determining the permeation rate of films in the "SimPerm" project.
This now makes it possible for the first time to simultaneously determine the permeation rate of water vapor and oxygen. Producers, users and developers of barrier films can now determine the gas permeability of protective films for organic light-emitting diodes (OLEDs), organic solar cells, tablets, food and other air-sensitive goods more precisely, realistically and cost-effectively than before. The project partner Sempa Systems GmbH soon wants to establish a new class of devices on this basis that can universally measure the various barrier properties of films.
Using infrared laser beams and fluorescence quenching, barrier films can be tested simultaneously for their water vapor and oxygen permeability. The measurement technology is used in OLED technology, medical technology and the food industry (Photo: © Amac Garbe/Fraunhofer IWS)
In order to enable measurements of the water vapor permeation rate (WVTR) and the oxygen permeation rate (OTR) simultaneously in just one device, the researchers combine laser diode spectroscopy for water vapor measurement with fluorescence quenching for oxygen measurement in one measuring cell. In order to achieve a sufficiently low detection limit for the concentration measurement of both permeates for ultra-barrier films, instead of a continuous nitrogen flow, nitrogen pulses now precisely control the concentrations of the water vapor and oxygen molecules that penetrate the barrier layer under investigation.
