Electronic displays that fit on clothing could power revolution in lighting

Apr 19, 2007

A thin film of plastic which conducts electricity and produces solar power could be the basis for a revolution in the way we light our homes and design clothes.

An international research project has begun that could help bring to mass-market organic light emitting devices (OLEDs), which could have far reaching technological implications and cut the cost of lighting by billion of pounds each year.

Because the devices are thin and flexible, lighting and electronic display screens could for the first time be created on almost any material, so that clothes and packaging can display electronic information.

The devices’ uses could vary from lighting that is many times more efficient than current bulbs to clothes whose colour can be changed at will and beer cans that display the latest football results.

At present, the devices are used as displays in some mobile phones and MP3 players, but they are not reliable enough for larger screens such as in TVs and computers as they stop working after a few months.

But now an international consortium of researchers, led by the University of Bath, UK, has begun an £850,000 ($1,700,000), three-year project to put the science behind the devices on a firmer basis, so helping make them efficient enough to be worth producing for the mass market.

The consortium, called Modecom, consists of 13 groups from nine universities and two companies. Three groups are from the UK, six from the USA, and one each from China, Belgium, Italy and Denmark. The European Union is funding the European and Chinese partners.

The devices exploit a discovery made around 15 years ago that some polymers have the unusual property of either turning electricity into light, or light into electricity, depending on how the devices are made.

Because these polymers are thin and flexible, they could be used in a multiplicity of ways:

• as a transparent window. This is like a conventional window during the day, but when it gets dark a switch is turned on and the entire window area emits light in a more efficient way than conventional or energy saving bulbs, promising huge savings

• in garments which could change colour at the press of a button

• in clothing which displays strips of the polymer which run off solar power, allowing electronic messages to be displayed which can be updated. This could be useful for the emergency services such as police or ambulance

• in packaging for common goods that could be made to display electronic messages such as health warnings and recipes, or could emit light

• as a source of solar power to top up mobile phones batteries

• as lightweight, solar power sources that could be rolled up and stored and which would also be ideal for people requiring electricity in remote locations, such as field researchers, mountaineers, sailors and military personnel.

The consortium is co-ordinated by Dr Alison Walker, of the University of Bath’s Department of Physics, who said: "This is a long-term project, and the contributions of many scientists are needed for its success.

“The experimentalists make measurements to test the efficiency of the devices, but it’s hard to get a clear picture of what is going on at present. This project is about making that picture clearer using computer models to develop the theory.

“Success in achieving the goals of cheap, efficient and long lasting devices is essential as we must do everything we can to reduce our energy costs.“

The polymer is made from chains of molecules, and is called organic because these contain carbon. Electrons and holes injected into the polymer film form bound states called excitons that break down under electrical current, emitting light as they do so.

Dr Walker’s part of the consortium’s research uses a mathematical technique called Monte Carlo analysis in which computer-generated random numbers are used to plot the paths of electrons, holes and excitons as they move across the film.

The results from this can be used to calculate how the chemical structure and impurities affect the device’s performance. Chemists can use this data to design more efficient materials.

The Modecom consortium will work on the molecular level and also look at the workings of the device as a whole. This research will also aid the understanding of the polymer materials used in plastic electronics in applications such as electronic paper and intelligent labels on groceries.

For a video of an OLED display: www.universaldisplay.com/video/2002foled257.wmv

Source: University of Bath

Explore further: Revealing faded frescos

Related Stories

Recommended for you

Revealing faded frescos

9 hours ago

Many details of the wall and ceiling frescos in the cloister of Brandenburg Cathedral have faded: Plaster on which horses once "galloped" appears more or less bare. A hyperspectral camera sees images that remain hidden to ...

Device could detect driver drowsiness, make roads safer

11 hours ago

Drowsy driving injures and kills thousands of people in the United States each year. A device being developed by Vigo Technologies Inc., in collaboration with Wichita State University professor Jibo He and ...

New capability takes sensor fabrication to a new level

Jun 30, 2015

Operators must continually monitor conditions in power plants to assure they are operating safely and efficiently. Researchers on the Sensors and Controls Team at DOE's National Energy Technology Laboratory ...

Smart phones spot tired drivers

Jun 30, 2015

An electronic accelerometer of the kind found in most smart phones that let the device determine its orientation and respond to movement, could also be used to save lives on our roads, according to research ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.