According to a report by IDTechEX*, the worldwide printed electronics market will be worth $74 million by 2030. The EU LEE-BED project was set up to support this rapidly growing market by building and operating a set of pilot production lines to aid in the development of innovative new products. What sets this project apart, however, are the inks: The partners have developed some novel conductive inks with unique capabilities like transparency or the ability to change colors depending on certain physical parameters. CEA-List came up with an in-line quality control method—currently implemented on a demonstrator—compatible with metal-particle-based ink formulations.
Here, CEA-List selected energy-dispersive X-ray fluorescence (EDXRF) for the metal nanoparticle inks. However, the main innovation lies in the combination of EDXRF with capacitive measurement and a special algorithm (and software) to bring the two types of data together in a useful way. The solution can check whether the ink’s particle concentration is homogeneous and detect any agglomerates or impurities that could negatively impact the quality of the finished product. Unlike optical control methods, it is not affected by ink color or concentration or by the size or type of metal nanoparticles. And, for a specific kind of ink, it can even be used to monitor synthesis by measuring the level of oxidation. This type of in-line control will be a prerequisite to volume production of new inks.
The lab demonstrator is now operational. Ultimately, LEE-BED Single Entry Point, the organization that is interfacing with customers, will be able to offer it as a new characterization and monitoring tool. One patent has already been filed, with a second one in the works.