LONDON - Light-emitting T-shirts may soon come to be used for electronic displays, thanks to a new Japanese screen-printing method of depositing a luminescent gel onto any surface, including paper and fabric.

Researchers at Dai Nippon Printing in Tokyo, who have made this advance, have revealed that the gel consists of a ruthenium compound that emits a bright light when a voltage is applied to it, along with an electrolyte and silica nanoparticles.

The electrolyte is a liquid salt, an ionic liquid that does not easily evaporate. It also prevents the ink from degrading, allowing displays to be printed onto surfaces without the need for a protective coating.

What makes this ink suitable for use with textiles is the fact that it will not wash off in water, say the researchers.

According to them, the silica nanoparticles blend with the light-emitting liquid to form a gel, allowing it to be printed onto different surfaces in discrete blobs, to form pixels.

Presently, the ink emits only reddish hues, reports New Scientist magazine.

The researchers, however, are trying to incorporate other metal compounds into their technique so as to emit green and blue light, which will eventually give them the whole spectrum.

Since the screen-printing technique currently allows only rough pixels to be generated, the images produced currently are fuzzy.

The researchers say that they are working on techniques to deposit the gel onto surfaces using an ink-jet printer, which would allow them to create smaller pixels and hence higher resolution at costs lower than those involved in lithographic techniques.

The company hopes to market the technology within five years.

It believes that its technique may pave the way for light-emitting posters, clothing, flexible displays, and new lighting applications. (ANI)