New e-paper could replace expensive electronic displays
Thu 23 Apr 2015
Researchers at the University of Tokyo have developed a cheap and durable e-paper technology which can be written and drawn on with a magnet.
By updating a prototype designed in the 1970s, the Japanese research team hopes that its new lightweight electronic paper could be used as a replacement for whiteboards and blackboards in classrooms, and as a cheaper alternative to expensive electronic displays. The team claims that the technology could eventually reduce reliance on real paper, curbing waste and deforestation.
The base technology, named ‘twisting ball displays’, was originally developed over 40 years ago and uses bicoloured microparticles moving around an elastic silicone sheet between two parallel electrodes. The microparticles change colour, displaying different charge properties on each side which causes them to rotate in the same direction of the electric field. If the direction of the voltage changes so too does the display colour.
![e-paper-technology[1]](https://thestack.com/wp-content/uploads/2015/08/e-paper-technology1.jpg)
In their new version the Tokyo researchers added a magnetic field to control the flow of particles. The black hemisphere of the microparticle contains a negative charge as well as a group of magnetic nanoparticles which pull towards the surface as a magnet is passed along the white display – making it possible to write and draw with a magnetised stylus. Applying a voltage then wipes the surface clean.
According to research lead Yusuke Komazaki the e-paper is low-cost, durable, and easily scaled. “Conventional electronic whiteboards are equipped with large LCDs or projectors and are very expensive, less visible in bright light conditions, heavy, and energy consuming,” said Komazaki. “If we fabricate super-large displays, it might even be possible to replace traditional blackboards in classrooms,” he added.
Komazaki also suggested that the colour combinations could be modified according to aesthetic preference or for specific needs by swapping the microparticle pigments.
The scientists plan to continue testing with increased amounts of black and white pigments in the microparticles to improve the display’s contrast and definition.
