A Cornell University engineering team has created a new kind of flexible display based on a perennially popular inspiration for scientists: the cephalopod. A study published today in Science describes how researchers developed a highly flexible, color-changing "skin" that senses pressure. It's one of many similar ideas that could one day end up in stretchy screens, soft robots, and other new technology.
Squid and octopus skin is, to put it bluntly, cooler than our own. By detecting light and flexing muscles in response, the skin can rapidly change color and texture to match its surroundings. A similar human-made material wouldn't just be perfect for camouflage, it could create electronic displays that fold, roll, and stretch. As the study's authors note, researchers have found multiple ways to potentially do this. Here, they've focused on a specific method for creating "skin" that lights up and detects touch while stretching to several times its original size.
The video above shows off three proof-of-concept designs for the technology. At their core, all three designs are made of thin rubber pixels — whether in a single strip, a grid of lights, or a moving robot. Each pixel is a five-layer "sandwich" with highly flexible silicone on the outside, two transparent and stretchy electrodes under that, and a central luminescent phosphor layer that produces color under electrical stimulation.
As the first section demonstrates, the resulting displays can be connected to electrical voltage and stay luminescent while being pulled like taffy. In a larger sheet, they can be poked, rolled up, and pulled in multiple directions while staying lit. Lastly, multiple panels of different colors can be built into a soft robot, lighting and dimming as it inflates and deflates three air chambers in sequence to move.
In the future, a more complex soft robot could use similar panels to display information. Or, the authors suggest, they could display different colors "in response to mood or the tone of the room." But they also note that before this skin can be used more widely, they'll need to make the panels more luminous, higher-resolution, and thinner. So for now, we'll have to be satisfied with light-up robot caterpillars.
Video courtesy of Cornell University.