Organic light-emitting diodes (OLEDs) have found their way into a number of industries in recent years. They have particular potential in the automotive industry, with OLED tail lights by Audi about to go into production. Audi is presenting prototypes of these tail lights and the current state of the art technology at the LOPEC Congress—the leading communications platform for printed electronics, which takes place between April 5 and 7, 2016 in Munich, Germany. Today, Stephan Berlitz, Head of Development, Lighting Functions and Innovations at Audi's base in Ingolstadt, provides an advance insight into the requirements that OLEDs deployed in the automotive industry will need to meet, how he sees the future of automotive lighting and his expectations of LOPEC 2016.
Mr Berlitz, you gave a presentation at LOPEC 2013 on organic light-emitting diodes in vehicle construction. Have there been any developments since then?
There have been lots! We have now reached the stage of going into production with OLED tail lamps and will be showcasing prototypes at LOPEC this year. The presentation I gave three years ago was very helpful in this respect—it generated contacts that enabled us to take several significant steps forward. We shall be making another plenary presentation at this installment of the LOPEC Congress that will give us the ideal opportunity to show that we are actually using OLEDs, and that we intend to support further developments in the field.
Do OLEDs need to meet higher demands when used in vehicles than for other applications?
Yes, it is always a challenge to adapt new technologies, such as the OLEDs we are discussing here, to the demands of the automotive industry. OLED table lamps and lighting installations for museums, restaurants and clubs have been around for a while, but vehicles do not travel around in air-conditioned spaces. OLEDs used in vehicle construction have to be able to withstand cold, heat and humidity, UV radiation and constant vibration. All of these things can reduce their lifespan. But that problem has now been solved. Our OLEDs are hermetically encapsulated and are just as stable as we have come to expect of LEDs.
What are the advantages of OLEDs over standard LEDs?
Regular LEDs are point light sources, which require a lot of development work in order to be able to produce an even light. OLEDs, by contrast, are radiating light sources that by their very nature provide a uniform illumination—and with a thickness of less than a millimeter. What's more, an OLED has a high quality appearance both while off and on, due to its clean and simple surface. That makes it ideal for our purposes, since design is an important aspect for Audi customers. Our vehicles are expected not only to get their owners from A to B but also to suggest a certain lifestyle.
Your colleague Dr Werner Thomas will be giving a plenary presentation at the 2016 LOPEC Congress. What will he be speaking about?
Dr Thomas will be setting out the current state of OLED technology in vehicle lighting, as well as discussing future developments. Once the light intensity of OLEDs can be further increased, they will be suitable for use as turn signals and brake lights. We are also working on flexible OLEDs. The glass-based OLEDs that we currently use are flat but rigid; OLEDs that use plastic foil substrates open up a whole new world of opportunities for the designers. We shall be presenting a prototype for these at LOPEC, too.
To what extent is LOPEC supporting the development of OLED technology and of printed electronics in general?
The great thing about LOPEC is the bandwidth of businesses and research institutes represented there. As an applications business we can make use of this breadth of activity and hold discussions with the specialists—the materials developers and OLED manufacturers—on the approaches we are taking. There is nowhere else in the world where it is so easy to come into contact with these experts. We will be talking about our ideas at LOPEC and hoping someone will say: "If you want that and that, then we should perhaps be researching this or that direction."
Looking further into the future, what is your vision of automotive lighting?
In the next 10 to fifteen years, we will be seeing innovations in vehicle lighting that we can scarcely imagine today. A vehicle's lighting equipment already acts as a form of communication—think brake lights, turn signals, and hazard lights, for example—and the driverless cars of tomorrow will need to interact even more powerfully with other road users. One vision we have, therefore, is of a three-dimensional OLED display covering the entire tail of the vehicle. We are also working on applying OLED coatings direct to the bodywork panels or integrating OLEDs into the windshield. There is a lot of development work to be done, though, before we can put those ideas into production.
What requirements and questions are you hoping to find solutions for at LOPEC?
As I said, automotive manufacturing places significant demands on lighting technology. Red OLEDs are already available that can meet our requirements in terms of intensity and stability. Amber ones will come next, and we also need a high quality white light. Once a white light acquires a green cast over time, it no longer meets our demand for premium quality here at Audi. At the same time, we also need a broader color spectrum for interior lighting. OLEDs are not suitable for headlights, because of their lower intensity, but they could produce some wonderful applications at the rear and in the interior. How do we put our ideas into practice? That is what we want to discuss with the people who have the technical skills in organic and printed electronics—and LOPEC is the ideal platform for that.
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