The Leitat technology centre near Barcelona is applying a new idea to an old problem. A team of technicians, using funding from the European Commission, has developed a smart-textile application for photo cells, which would allow garment manufacturers to meet consumer demand for clothes that keep them warm in winter and cool in summer.

Laurent Aubouy of the Leitat research and development team says that a summer garment incorporating the photo-cell idea could create a cooling effect of 8.3 degrees Celsius in sunny weather, and of 3.7 degrees on cloudy days. In winter, the same thermoregulatory system would be able to increase the wearer’s temperature by up to 13.5 degrees in sunshine, and by 8.3 degrees in cloudy conditions.

The idea centres on the Peltier effect, with the smart-textiles transferring heat from one side to the other using electrical energy from the photo cells. “We are talking here about an active process,” Mr Aubouy argues. “Ventilation is not an active process. With just ventilation in a garment for summer wear, you can only remove humidity. With this system you can have real thermo-regulation.”

He claims that polymers with photo-cell functionality have already begun to appear.

The Leitat centre has spun off a company called Suni-Lei to try to make the idea work commercially, with sportswear one of the possible areas of application. “We are looking for industrial partners to help us bring this to market,” Mr Aubouy concludes. “For example, we want to improve the mechanical integration of Peltier cells into textiles to allow us to make easy-care garments.”