Technology promises glowing books

Road signs that illuminate themselves and books that glow so they can be read easily in a dingy room are just two applications of a new smart plastic developed at Napier University, Edinburgh, UK.

Professor Janos Hajto has combined fluorescent molecules into a polymer that will amplify any ambient light by up to 30%.

If the plastic was incorporated into a book's pages, for example, the reader could follow the text in the dimmest of conditions.

"The applications are limitless," Professor Hajto told the BBC. "You can make a full-colour display for computers, for videos and for advertisements because you can collect this light without electricity."

Researchers worldwide are racing to develop new display technologies, especially those that exploit the low cost and ease of manufacture of plastics. Scientists predict a flood of new products, including TV screens that can be printed on clothing or rolled up and put in a pocket.

Professor Hajto has embedded a fluorescent dye in a polymer to make optical fibres which will channel light in one direction.

"Light goes into the fibres and is absorbed by the dye molecules," he said. "They re-emit the light (they fluoresce), but because they are in the fibres the light cannot escape and is directed to the ends of the fibres. The longer the fibre, the more light you collect.

"We have shown that you can make the light at the end of the fibre 30% brighter than the surrounding light."

Professor Hajto said the technology varied with ambient conditions to maintain the contrast. He said a road sign made with the new material, for example, would be 30% brighter whether it was viewed at dusk or at midday.

The importance of plastics in the emerging visual display technologies was recognised last week by the Nobel Foundation in Sweden. It awarded its prestigious chemistry prize to the three men who first demonstrated how plastics could be modified to conduct electricity.