Electronic Paper Turns a Page£¨3£©
E Ink's microcapsules are filled with a clear liquid that holds very small particles£®Some particles are black£®Some are white£®All of the particles have an electrical charge£®To make a sheet of electronic paper, engineers spread millions of the particle-filled microcapsules onto a piece of plastic£®
Because opposite electrical charges attract, applying a positive electric field to a microcapsule causes negatively charged black particles to rise and become visible-just like answers in a Magic 8-Ball£®The positively charged white particles sink£®So you would see a black dot at this spot£®
By controlling electric field patterns, engineers can decide which particles rise to the top£®The resulting patterns of black and white dots, viewed from a distance, create the words and pictures you see on the sheet£®To move the ink around, computer programs simply change the electric fields£®The pattern of black and white dots changes in turn£®
Electronic paper is much easier to read than typical computer screens, Bischoff says£®Many traditional displays count on lights inside the machine to light up the screen from behind, for example£®That makes such screens easy to see when you're indoors, but they're hard on the eyes and difficult to read in bright sunlight£®