Researchers have printed complete integrated circuits with more than 1,000 organic electrochemical transistors. Printing electronic circuits with a line width of approximately 100 micrometers places high demands on print technology. To solve the problem, the team developed screen-printing frames with meshes that can print extremely fine lines and printing ink with the right properties. The material used is the polymer PEDOT:PSS.

At least three challenges have been dealt with: reducing the circuit size, increasing the quality such that the probability that all transistors in the circuit work lie as close to 100% as possible, and solving integration with the silicon-based circuits needed to process signals and communicate with the surroundings.

Printed circuits were used to create an interface with traditional silicon-based electronic components. Several types of printed circuits based on organic electrochemical transistors were built. One of these is a shift-register, which can form an interface and deal with the contact between the silicon-based circuit and other electronic components such as sensors and displays. This results in a silicon chip with fewer contacts, which needs a smaller area and is less expensive.

The development of ink to print the thin lines and improvements of the screen-printing frames contributed not only to the miniaturization process but also to achieving higher quality. More than 1,000 organic electrochemical transistors can be placed on an A4-sized plastic substrate and can be connected in different ways to create different types of printed integrated circuits.

These large-scale integrated circuits (LSI) can be used, for example, to power an electrochromic display — itself manufactured as printed electronics — or another part of the online electronic world that the Internet of Things brings.

For more information, contact Magnus Berggren at This email address is being protected from spambots. You need JavaScript enabled to view it.; +46 11 36 36 37.