Develop your prototype with one of the most energy-efficient display technologies that can replace LCD

The testbed Printed Electronics Arena is operated by RISE, and this is where world-leading, tailor-made displays are developed with printed electronics. The display's unique properties: thin, flexible, and robust design, make them versatile. They can be designed for monitoring temperature as a cold chain indicator or as smart bandages that indicate when they need to be changed.

This is how the electrochromic display works

Electrochromic displays (ECD) are an electrochemical component. It is based on knowledge of electronics, as well as organic chemistry. The core of the technology is an ink that changes color (chroma) at different voltages (electro). It shifts in color from dark blue to light gray. The contrast ratio is high enough to create visual indicators and to turn on and off different segments.

RISE and the display manufacturer Ynvisible have developed displays in different colors. What is unique about the display is that it requires a very low voltage and low energy consumption to create a color difference. As little as 1.5 volts is needed to create a color difference to communicate a message. The display has a temporary memory, also called semi-bistability, which means that it can still be read without a power supply for several hours. Afterward, it slowly returns to its off position. The temporary memory is a contributing factor to the energy efficiency of the electrochromic display.

Manufacturing electrochromic display

Electrochromic displays are built in several different printing steps with screen printing. Some display structures require a few printing steps and materials, while high-performance displays may require up to ten printing steps. The printing process begins with applying ink to a substrate. The substrate is usually PET plastic, but it can also be paper or some form of moisture barrier.

All inks – electrically conductive, ion-conducting, graphic, and insulating inks – are printed with conventional screen-printing equipment. It is a very cost and energy-efficient way to manufacture electronics. The displays can be screen printed in a manual or semi-automatic sheet-to-sheet production, which is well suited for prototypes and small volumes. They can also be printed in a fully automated roll-to-roll production where millions of displays can be produced at a low cost.

 ^{At Printed Electronics Arena, the prototypes are screen-printed in a semi-automatic sheet-to-sheet production.}

The various inks are either hardened by thermal curing or UV curing. Then the electronics are printed on the substrate in different structures that form conductive paths. The active materials that conduct electricity can be carbon, silver, or the semiconductor component PEDOT: PSS. Finally, the displays are encapsulated with a protective film that repels moisture and, to a certain extent, UV light.

20 years of research have gone into developing RISE's patented electrochromic display technology. The chemistry and materials research behind the display technology originates from Linköping University and RISE. Printed Electronics Arena is run by RISE in close collaboration with Linköping University. The testbed is financed by Vinnova, Region Östergötland, Norrköpings kommun, and the Knut and Alice Wallenberg Foundation.

Read more about RISE's collaboration with Ynvisible and the development of an energy-efficient display based on RISE's many years of research. Due to energy harvesting, the display can be used completely without a battery and create a smart logistics solution for pharmaceuticals.