A groundbreaking type of color e-paper is capable of showcasing vivid, high-resolution, full-color images and videos with minimal power consumption, heralding a potential new era for display technologies.

Unlike conventional LED screens, which produce colors through the emission of red, green, and blue light, e-paper screens utilize small molecules to generate images. Historically, these screens were restricted to black and white, but advancements have now allowed for color displays. However, they still face challenges in updating quickly enough for video playback.

To address this issue, Kunli Shion and their team at Uppsala University in Sweden have engineered electronic paper featuring pixels constructed from tungsten oxide nanodisks. Each pixel measures roughly 560 nanometers, resulting in an impressive resolution of 25,000 pixels per inch (PPI), whereas typical smartphone displays generally have resolutions in the hundreds.

The tungsten oxide nanodiscs are designed in various sizes and spacings to reflect distinct bands of light. By arranging them together, a range of colors can be created, with brightness adjustable through short electrical pulses that position ions within each disk. Once set, these ions maintain their placement, allowing the color to persist without a continuous power source.

The researchers constructed an e-paper display that measures just 1.9mm by 1.4mm, roughly 1/4000 the size of a conventional smartphone display, and utilized it to showcase a 4300×700 pixel segment of Gustav Klimt’s The Kiss – achieving remarkable resolution for such a compact device. It is also capable of refreshing approximately every 40 milliseconds, making it suitable for video display.

Another significant advantage of this novel e-paper technology is its remarkably low energy consumption, as noted by Xiong. The display utilizes about 1.7 milliwatts per square centimeter for video and around 0.5 milliwatts per square centimeter for still images.

“What I find impressive about this development is its capacity to support video at a rapid pace while consuming minimal energy, as each element remains switched after being activated,” comments Jeremy Baumberg from Cambridge University.