Researchers at The University of Manchester have developed battery-powered textile yarns that can be used to make clothing glow in the dark. The yarns have been developed by The William Lee Innovation Centre (WLIC), based in the University’s School of Materials – and have the potential to be incorporated into clothing worn by cyclists, joggers and pedestrians.

The development, made from electroluminescent (EL) yarns, emits light when powered by a battery.

Dr Tilak Dias, head of the WLIC, said: “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.
The yarn consists of an inner conductive core yarn, coated with electroluminescent ink – which 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 EL yarn is powered, the resultant electrical field between the inner and outer conductor causes the electroluminescent coating to emit light. 
 
“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.”

The team also think the yarn could be used for flexible woven or knitted road safety signs that communicate written instructions.