Philips offers new e-ink possibilities in color
By Paul Ridden
December 14, 2009
Rather than using e-paper technology just for displays, the research arm of Dutch technology company Philips Electronics has developed a relatively cheap, light, thin and energy efficient means of turning the whole of the surface of a device into a digital canvas. E-skin pixel manipulation sees different colored particles in a clear suspension activated by an electric field to produce a single vivid color pixel or a mix of colors and shades.
Electronic paper (e-paper) utilizes a process called electrophoresis where colored particles in a clear suspension carrying a surface charge are controlled by administering an electric field perpendicular to the surface, forcing them to gather at the top of a pixel and so creating darkened areas. Placing activated and non-activated pixels together forms words and pictures.
In developing its electronic skin (e-skin) technology, Philips researchers applied the charge parallel to the surface causing independently controlled charged color particles to spread across the pixel. When the pixel is reset, the particles are masked and the pixel returns to a transparent state. The researchers incorporated a gate electrode into each pixel to control the color saturation or shape of each color.
The upshot is that instead of only using such technology within the confines of a dedicated display area, e-skin can be used on the whole surface of a device. So it could change the color of a mobile phone to alert the user of an incoming call, change the appearance of a kettle to indicate when water has boiled or change the appearance of a gaming device to match the mood of the game being played.
But Philips has its eye on larger surfaces too, according to Kars-Michiel Lenssen, Principal Scientist at Philips Research: "The first applications using the technology could be e-skins for small devices such as MP3 players or cell phones. However, the technology is highly scalable. In the future it will be possible to use e-skins to bring new color and a new aura or vibe to much larger equipment. Just as Philips' Ambient Experience uses light and color to make hospital diagnostic rooms far more welcoming, a large e-skin could make the concept fit for the MRI or CT scanner itself, potentially putting patients more at ease."
The technology is thin and energy efficient enough to also be used in wallpaper or glass which could change the appearance or mood of whole rooms at the flick of a switch or if used in window panes, could effectively become digital window blinds by regulating the amount and the color of light coming through.
"What really excites me about the Philips e-skin technology is that you could add it anywhere. It doesn't need a lot of power or batteries, and it really is a thin skin that doesn't add weight to an object," commented Elise van den Hoven, of the Eindhoven University of Technology in the Netherlands. "When it's not on, it can be completely camouflaged or even transparent so you can still have your own pattern underneath. There aren't many technologies that can do all that."
The main aim of the research is geared towards product personalization or ambient scene creation but Philips says it's open to licensing the technology to applications such as e-paper displays.