Printed electronics in 3D, also known as 3D structural electronics, equip all kinds of objects with additional electronic functions. New materials and printing processes form the basis.
It is integrated in sneakers and T-shirts, in vehicles, household appliances and many other everyday objects: Printed electronics is revolutionizing many industries because it is so lightweight, thin, flexible and robust that it can be discreetly integrated into virtually any object of any shape. “Printed electronics makes it possible to meet the growing demand for smart products with sophisticated additional electronic features—with a great deal of design freedom,” emphasizes Dr. Klaus Hecker, Managing Director of the industry association and LOPEC co-organizer OE-A (Organic and Printed Electronics Association). For some years now, Hecker has also observed an increasing interest by various user industries in customizable manufacturing processes:
“If the digital manufacturing technologies inkjet printing and laser processing are cleverly integrated into mass production environments, products can be individualized in-line,” explains Professor Reinhard Baumann of the Fraunhofer Institute for Electronic Nano Systems ENAS: “As a result, unique items can be manufactured using mass production methods.” Researchers from six Fraunhofer Institutes are involved in the project “Go Beyond 4.0”, which Baumann coordinates. In the project they develop, for example, printed heating structures embedded in glass or carbon fiber reinforced plastics for aircraft construction as well as a smart car door with conductor paths, sensors, switches and light-emitting diodes, some of which are printed directly onto the car’s body parts.
Printing inks and pastes with electronic properties and flexible carrier materials that build a stable bond are the foundation of 3D structural electronics. Dr. Hongye Sun of the Karlsruhe Institute of Technology has developed extremely stretchable silver-based inks. The concept is based on the so-called capillary suspension: A substance that does not mix with the main component of the printing ink builds bridges between the silver particles.
Several production processes are now available for 3D structural electronics. An alternative to direct printing of 3D parts is the thermoforming of 2D components printed on plastic. Two companies, based in Saxony, a Federal State of Germany, offer systems for this purpose: Adenso has developed a roll-to-roll printing technology with integrated forming process for the mass production of 3D electronics. watttron, in turn, will show a special heating system for thermoforming: It is based on many small heating pixels arranged in a matrix the temperature of which can be individually programmed and controlled. In addition to thermoforming, injection molding is particularly suitable for the production of 3D structural electronics. Pioneer in this area is the Finnish company TactoTek. Their injection molding technology IMSE (Injection Molded Structural Electronics) enables the integration of printed circuits and other electronic components in 3D parts.
“The materials and techniques best suited for the production of 3D structural electronics are dependent on the respective application,” emphasizes Hecker. „As an industry association, we offer interested parties from all industrial sectors a comprehensive range of decision support.“