In line with the new e-ink tech devices being used in devices and LCD technology, Philips unveils colored e-papers to entice our imagination and visual needs. For some background, existing e-ink tech in devices like Sony’s Reader and the Amazon Kindle use electrophoresis. This technique sees white particles suspended in a dark liquid. When an electric field is passed through them, they get happy, more vertically up and down, and you can read Stephen King on your Kindle.
Each pixel is made up of two microcapsule chambers: one containing yellow and cyan particles, the other, below, containing magenta and black particles. Within each microcapsule, one set of colored particles is charged positively while the other is charged negatively.
By carefully controlling the voltages at electrodes positioned on the edges of the pixels, it is possible to spread the colored particles across the pixel or remove them from view altogether by hiding them behind the electrodes, says Lenssen. This means that different shades of color can be achieved by controlling how many of each group of colored particles are visible. To create white, all of the particles are simply shifted to the side to reveal the white substrate beneath the two microcapsules.