BTS ÉLECTRONIQUE / ÉLECTROTECHNIQUE
Plug your palmtop into your threads and throw away those batteries
Your sweater could one day provide all the power you need to run your MP3 player, mobile phone or palmtop computer - as long as you are not standing in a darkened room. The idea comes from scientists in Germany, who have developed synthetic fibres that generate electricity when exposed to light. The researchers say the fibres could be woven into machine-washable clothes to make the ultimate in portable solar cells.
When photons hit the surface layer, they displace electrons that then flow through the middle layer to the electron-poor layer. This current can be used to power devices or charge batteries.
German scientists developed their photo-voltaic fibres while trying to deposit amorphous silicon on curved surfaces. They found that by depositing different layers around a fibre, they could build up the photo-voltaic sandwich in cylindrical form. Any substrate that look likes a cylinder - from wires to fibre-optic cables - works, provided it can withstand the ultraviolet radiation and 100° C temperatures used in the deposition process.
One of the biggest challenges facing the German team is creating contact with each strand in a fabric, says Chris Chapman, development director of ElectroTextiles in Buckinghamshire - a company which specialises in making electronic devices out of a fabric. "The thing that scuppers most things with fabrics is getting power in and out of it", he says.
As far as fashion sense is concerned, colour should not be a problem. Although the fibre is transparent, it can be made to take on different colours by adjusting the thickness of a transparent protective coating.
Duncan Graham-Rowe, New Scientist
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