Researchers at the University of Michigan have introduced a groundbreaking flexible screen technology that could revolutionize how we think about displays. The team claims this flexible screen technology represents one of the first instances where mechanical materials are used for encryption, information processing, and computing via magnetic fields.
“It’s one of the first times where mechanical materials use magnetic fields for system-level encryption, information processing, and computing. And unlike some earlier mechanical computers, this device can wrap around your wrist,” said Joerg Lahann, professor of chemical engineering at the university and a co-author of the study.
The technology functions similarly to an Etch-A-Sketch. When shaken, the display is erased, but the image is stored in the magnetic properties of the beads within the screen. When the screen is exposed to a magnetic field again, the image reappears. These beads, alternating between orange and white hemispheres, act as pixels. The orange side of each bead is filled with magnetic particles, which rotate under the influence of a magnetic field to create the color contrast necessary for the display.
The screen’s pixels are programmed to show either orange or white based on their exposure to different magnetic field strengths. As a result, the magnetic properties of the pixels can be reprogrammed, allowing for the display of different images. The technology allows for both permanent and temporary displays—relatively weak magnetic fields can alter some pixels, while others, made with stronger neodymium particles, require a powerful magnetic pulse to be rewritten.
For more intricate designs, users can expose the screen to a grid of magnets with varying strengths and orientations. This manipulation of the magnetic field causes specific pixels to flip between orange and white, thus encoding an image.
“This device can be programmed to show specific information only when the right keys are provided. And there is no code or electronics to be hacked. This could also be used for color-changing surfaces, for example, on camouflaged robots,” Abdon Pena-Francesch, assistant professor of materials science and engineering at the University of Michigan, emphasized.
One of the more fascinating aspects of this screen’s design is its inspiration from the natural world. The researchers studied the pigment sacs in the skin of squids and octopi to determine the optimal size and distribution of pixels.
“If you make the beads too small, the color changes become too small to see. The squid’s pigment sacs have optimized size and distribution to give high contrast, so we adapted our device’s pixels to match their size,” explained Zane Zhang, a doctoral student in materials science and engineering and the study’s lead author.
In its standard state, a weak magnetic field, such as that from an everyday magnet, can reveal an image. However, private images can be hidden and revealed only when a second magnetic grid selectively modifies the pixels’ polarization, allowing for dual use as both a public and private display.