A microfluidic film which allows magazine-quality reflectance and video-rate switching in electronic paper is reported this week in Nature Communications. Achieving a high reflectance in e-paper is important for this technology to be competitive in displays of portable electronic devices.
Jason Heikenfeld and colleagues developed an approach for e-paper in which coloured ink is moved through a white porous film to show in front of or hide behind it. Pixels created using this method have a reflective area larger than 90%, resulting in a reflectance for white that exceeds magazine quality (>76%). The film is engineered to be assembled without alignment to the control electrodes, significantly simplifying the fabrication process. The authors demonstrate a 150 pixel per inch device with switching times of 15 milliseconds, compatible with video-rate speeds.
The authors note that this proof-of-concept device shows competitive performance when compared with existing commercial displays based on electrophoretic or liquid crystal technologies.