Light-powered screen

A computer screen that saves power by harvesting ambient light has been
invented by Janos Hajto of Napier University in Edinburgh. He mixed fluorescent
dyes with a polymer to make optical fibres. The dye molecules fluoresce,
producing light which is reflected to the tips of the fibre. Hajto arranged
fibre tips to form a grid of dots, which he covered with a layer of liquid
crystals. Switching the liquid crystals hides some dots and leaves others
exposed—turning them off or on.