With special electronic ink that consists of tiny particles!
- By applying electrical charges, these particles can be arranged and text/images displayed.
- The display is maintained even without power supply (bi-stability).
- To change the display, an opposite charge can be applied to reset the particles.
The heart of ePaper is the so-called electronic ink. It consists of a film of viscous gel in which ink particles are embedded. These particles are charged differently, e.g. white positively and black negatively. This film is enclosed at the top and bottom by transparent electrodes, similar to a liquid crystal in a TFT cell. When a charge is applied to the electrodes, the color particles migrate towards the opposite charged side. In this way, a complete image is created from individual pixels.
Because the particles are enclosed in a viscous gel, they retain their position even when the external field is switched off. The effect: The image is retained permanently without the need for further energy.