Dr. Tobias Kraus and his team of researchers at the German Leibniz-Institut für Neue Materialien (INM) developed this new printing technique. Their goal was to reach a new level for ultra-thin and ultra-flexible electronics. A combination of ink that contains gold nano-strings and pre-structured stamps makes this possible. The clue: The ink’s capacity to self-organize its structure makes the printed conductive even if bent.
To produce these flexible conductors, the scientists spread the nano-ink widely onto a surface. A stamp with a pre-set structure that presses the ink into any form or shape is then applied. “The nano-strings follow the structure of the stamp since they are super thin and flexible”, explains Kraus. While the ink dries up, the single strings form bundles that connect to each other later on in grids – the basis for the conductors. To condense the bundles, ligands which stabilize the nano-threads inside the ink are eliminated with plasma. The result is a conductive, transparent, and thin grid that can be used for various flexible electronics.
Kraus and his team are optimistic that they have not reached the limit for this new printing technique. “We are able to regulate the thickness of the grid structures directly through the gold concentration in the ink. Through that we can reduce the amount of gold needed in the printing process. Our next goal is to use these learnings and apply them to other metals”, says Kraus.
For more information on this printing method click here and here.