Peter Andersson Ersman
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:
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
The Inga project