Consortium develops unbreakable displays for cars

September 06, 2013 // By Christoph Hammerschmidt
Curved displays for automotive applications need to be flexible to a certain extend - besides being robust and lightweight. For applications in the automotive industry, research project LiCRA (Liquid Crystals for Robust Applications) is developing particularly tough yet lightweight full-colour displays. These screens are base on plastic foils as substrates instead of the glass substrates today found in most display screens.

Partners in the LiCRA project are the Stuttgart University as well as British company Plastic Logic, Etkes and sons from Israel, chemical and Life Science company Merck KGaA, LOFO High Tech Film GmbH and Micro Resist GmbH. The researchers from the Stuttgart University will jointly with Plastic Logic develop the processes for the production of plastic foil-based liquid crystal displays. Toward this end, Plastic Logic will further develop and adapt a technology presently used for monochrome e-paper displays based on organic thin film transistors. The Stuttgart scientists will dig into process technology for the assembly of such displays. Challenging in this context is the fact that all processing has do be done at low temperatures. Also the flexibility of the substrates (or the lack of flexibility) poses challenges that have to be overcome.

In addition, the Stuttgart University is conducting research on how to integrate OLEDs into the liquid crystal cells - these OLEDs have to emit polarized light. The advantage for future commercial displays: With this approach, additional backlighting can be omitted and one of the two polarizer foils used in today's LCDs can be dropped. A backlight technology suited for robust, lightweight and flexible displays will be developed by Etkes and sons. Micro Reisist will, within the scope of the project, develop materials and processes for nano imprint lithography. In contrast to conventional lithography where a photoresist layer is exposed to ultraviolet light and then developed much like a photographic film, in nano imprint lithography the desired structures are directly transferred to the carrier material by means of a three-dimensional stamp.

LOFO High Tech Film will provide the plastic films required for implementing these flexible LCDs. The research project attaches great importance to minimizing size variations during the subsequent LCD production process. Equally important is minimizing the optical double refraction since both effects would lead to deteriorating the optical properties of the display. LOFO owns a technique to