Packaging and clothes could display electronic information such as this warning on yoghurt not to eat it. Thin, flexible devices may allow lighting and electronic display screens to be created - for the first time - on almost any material.

　　A MASSIVE change in the way we design clothes and light our homes could come about with the use of a thin film of plastic that conducts electricity and produces solar power.

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

　　The devices are thin and flexible allowing lighting and electronic display screens to be created - for the first time - on almost any material, meaning that even clothes and packaging could display electronic information.

　　These super-OLEDs could warn if the food in your refrigerator is still good to eat. And at an emergency, the jacket of a police officer, ambulance crew or fire-fighter could flash warnings or directions to anyone nearby or passing.

　　The use of such devices could vary from lighting that is many times more efficient than today’s light-bulbs - to clothes whose colour can be changed at will, and drinks cans that display the latest sports 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 because they stop working after a few months.

　　Now, an international consortium of researchers, led by the University of Bath in the United Kingdom, has begun a three-year project costing 850,000 pounds to put the science behind the devices on a firmer basis, therefore helping make them efficient enough to be worth producing for the mass market.

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

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

　　“Because these polymers are thin and flexible, they could be used in many ways, such as a transparent window. This appears to be 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.”

　　Furthermore, clothing could display strips of the polymer that run off solar power, allowing electronic messages to be displayed and that can be updated. This could be useful for the emergency services.

　　The OLEDs could be used also:

　　* 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 phone 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, on land or sea.

　　The consortium is coordinated by Dr Alison Walker, of Bath University’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 is hard to get a clear picture of what is going on at present.

　　“This project is about making that picture clearer [by] using computer models to develop the theory. Success in achieving the goals of cheap, efficient and long-lasting devices is essential because we must do everything we can to reduce our energy costs,” added Dr Walker.

　　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.

　　Bath is one of the UK’s leading universities, with an international reputation for quality research and teaching. The university has strong links with its community, offering its facilities, business acumen and academic expertise to people and businesses.  (Source: British Consulate-General in Chongqing)