FABRICS woven from light-sensitive fibres could soon be embedded in computer and projector screens, making it possible to control computers by tracking the position of laser pointers, or other light sources, on the screen.
Yoel Fink of the Massachusetts Institute of Technology and his colleagues made the fibres using techniques borrowed from the optical fibre industry. The researchers started with a rod a few centimetres thick consisting of a semiconducting core lined with metal wires, which in turn is sheathed in a layer of polymer. The rod was heated to 300 掳C and then drawn into a fibre several hundred metres long and less than a millimetre in diameter (Nature, vol 431, p 826).
鈥淭here were many messy disasters,鈥� Fink says, but once the team found materials that melted at the same temperature and flowed in the same way, 鈥渋t worked beautifully鈥�.
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A beam of light shining on any part of the fibre dislodges electric charges in the semiconductor, and these affect the voltage in the fibre鈥檚 metal wires. By sensing current changes in a grid of such fibres, Fink can pinpoint a light source. The team wove the fibres into a fabric about 30 centimetres square.