Researchers at the University of Manchester in the UK have developed high-tech battery powered textile clothing that glows in the dark.
Clothes made of this material could come in handy for cyclists, joggers and pedestrians on dark winter days, scientists at The William Lee Innovation Centre (WLIC), in the University's School of Materials, who developed the product, say.
The high visibility jackets currently being used by emergency services, cyclists and highway maintenance workers - depend on external light sources to glow.
As such, they tend to be ineffective in low light situations. Since they always require a light source from something like vehicle headlights to make them visible, there is often the risk of the wearer being seen too late.
Clothes made of the electroluminescent yarn, however, allow the wearer to be permanently visible, thereby improving his/her personal safety.
The yarn consists of an inner conductive core yarn, coated with electroluminescent ink - which means it emits light when an electric current is passed through it - and a protective transparent encapsulation, with an outer conductive yarn wrapped around it.
When the electroluminescent (EL) yarn is powered with an inverter, the resultant electrical field between the inner and outer conductor causes the electroluminescent coating to emit light.
The emission of light occurs between the contact points between the outer yarn and the inner yarn.
WLIC head Dr Tilak Dias says the EL yarn is a novel technology, which emits light when powered by a battery. Its development is based on thin film electroluminescent technology, he says.
He says apart from being incorporated into clothing worn by cyclists, joggers and pedestrians, the EL yarn could also be used to weave or knit flexible road safety signs that communicate written instructions.
"At the moment, the EL yarn we have developed is less flexible than conventional yarns. But it is more flexible than current optical fibres that are incorporated within fabrics to provide illumination. EL yarn can be easily incorporated into a knitted or woven fabric and the resultant active illuminating fabric provides illumination when it is powered," says Dr Dias.
"The luminance of a single strand of the EL yarn is greater than that of photoluminescent glow yarns, which are currently used in some high visibility applications. Weaving or knitting the yarn in a particular manner, so that more yarn per unit area is achieved, improves the luminance of the EL yarn," he adds.