Liten, a CEA Tech institute, has been investigating printed electronics on flexible organic substrates for more than a decade. A milestone was recently achieved in research conducted under the EU ATLASS project: For the first time ever, transistors were printed on a plastic substrate on a pilot fabrication line with high enough levels of performance and yields to enable the fabrication of complex circuits and subsystems. Previous proof-of-concept prototypes had only addressed discrete circuits or components.
The research, a joint effort with ink and printer manufacturers, allowed Liten to improve the materials and processes utilized (and, especially, the engraving of the printing rollers) to obtain the yields necessary for scale-up. The process was also made more reliable: The resulting defect rates were very close to zero and component reproducibility was excellent. Several sample runs of several hundred to several thousand transistors were produced with zero defects (100% of the components produced were functional).
Improving the technology and bringing it to a greater degree of maturity allowed the researchers to create functional demonstrators built on printed transistors for IoT and smart sensor surfaces. The technology is now ready to be tested for a wide range of other applications.