The research team led by Tomke Glier from the University of Hamburg is demonstrating the potential of their process with a flexible capacitor, among other things. "Functionalizing 3D-printable polymers for different applications was the goal of this study," reports Michael Rübhausen, physics professor at the Center for Free-Electron Laser Science (CFEL), a cooperation between DESY, the University of Hamburg and the Max Planck Society. "With our novel approach, we want to integrate electronics into existing structural units and make components more intelligent in terms of space and weight".
Rübhausen led the project together with DESY researcher Stephan Roth, a professor at the Royal Institute of Technology in Stockholm. Using the bright X-ray light from DESY's PETRA III research light source and other measuring methods, the team precisely analyzed the properties of the nanowires in the polymer. At the heart of the technology are silver nanowires, which form a conductive braid. These wires are typically several tens of nanometers thick and 10 to 20 micrometers long. X-ray analysis shows that the structure of the nanowires in the polymer is not changed, but that the conductivity of the braid even improves thanks to compression by the polymer, as the polymer contracts during the curing process.
The silver nanowires are applied to a substrate in suspension and dried. For cost reasons, the aim is to achieve the highest possible conductivity with as few nanowires as possible. This also increases the transparency of the material. In this way, layer by layer, a conductive path or surface can be produced. A flexible polymer is applied to the conductive tracks, on which conductive tracks and contacts can in turn be placed. Depending on the geometry and material used, various electronic components can be printed.