Printed Active Matrix Addressed Electrochromic Displays

ProjectThe Inga project: Matrix-addressed displays

The Inga project: Matrix-addressed displays

The Inga project was a collaboration between Acreo, Lintec Corp. (Japan) and Linköping University. It was partially funded by VINNOVA.

The primary targets of the project were:

  • Flexible electrochromic pixelated displays
  • Pixelation allows for any message to be shown on the display
  • To develop two updating techniques; passive and active matrix addressing
  • To utilize printing and/or coating techniques in the manufacturing process
  • All together, to enable high-volume and low-cost manufacturing of electrochromic displays
  • Technical data and examples of applications:
    • Low-voltage operation; < 3 V
    • Pixel size ~ 1 sq. mm
    • Fill factor ~ 90 %
    • Displays for advertising purposes

Passive matrix addressed electrochromic displays manufactured by printing techniques have successfully been demonstrated. The addressability of unique electrochromic pixels in the resulting display is obtained by the introduction of a threshold voltage that is generated by combining a carbon-based counter electrode with a PEDOT:PSS-based pixel electrode that together sandwiches a polyelectrolyte. The video clip shows the updating sequence of a printed passive matrix addressed display containing 16 x 16 uniquely addressable electrochromic pixels. The updating was performed without cross-talk effects at a scan rate of 100 ms per row and an updating voltage of 2.4 V, and the message ‘‘YOU WIN’’ could be observed after a few cycles. Another printed passive matrix addressed display containing 7 x 128 uniquely addressable electrochromic pixels have successfully been updated without cross-talk effects. This is, so far, the display with the largest number of pixels that has been demonstrated. However, this is not due to a limitation of the technology, but rather due to a limitation of the available number of I/Os of the external addressing electronics.

The project resulted in several patent applications and journal publications:
• Printed passive matrix addressed electrochromic displays, Organic Electronics, vol. 14, pp. 3371-3378, 2013
• Fast-Switching Printed Organic Electrochemical Transistors Including Electronic Vias Through Plastic and Paper Substrates, IEEE Transactions on Electron Devices, vol. 60, no. 6, pp. 2052-2056, 2013
• Fast-switching all-printed organic electrochemical transistors, Organic Electronics, vol. 14, no. 5, pp. 1276-1280, 2013
• Flexible active matrix addressed displays manufactured by printing and coating techniques, Journal of Polymer Science Part B: Polymer Physics, 51, 265-271, 2013
• Improving the color switch contrast in PEDOT:PSS-based electrochromic displays, Organic electronics, 13, 469-474, 2012

Contact: peter.andersson.ersman [at]