This Soft, Flexible, Low-Power Display Can Stretch Like Rubber — Making It Ideal for Wearables

Researchers from the University of British Columbia and CY Cergy Paris Université have developed a stretchable, flexible color-changing display which could prove perfect for use in wearable devices.

"This device is capable of fast, real-time and reversible color change," explains lead author Claire Preston, of the display technology developed as part of her master's degree in electrical and computer engineering. "It can stretch up to 30 percent without losing performance. It uses a color-changing technology that can be used for visual monitoring. And it is relatively cheap to manufacture."

Color-changing displays are a tried-and-tested technology, while flexible electronics aren't exactly a new invention — but combining the two has always been a challenge, resulting in complex devices with limited quality. Using a conductive polymer combined with an ionic liquid, known as PEDOT:PSS, the team overcame both problems: "[We created] a stretchable electrode that acts as both the electrochromic element and the ion storage layer," Preston explains. "This simplifies the device's architecture and eliminates the need for a separate stretchable conductor."

The resulting prototype is transparent and the texture of a stiff rubber band. When pulled, it can stretch up to 30 percent in width — while retaining its ability to switch colors in under seven seconds. One released, the display returns back to its normal dimensions without damage — a property which, combined with its low power draw, could make it ideal for wearable electronics and other use-cases where a display needs to conform to a non-flat surface.

"The potential uses for this stretchable display are significant," claims senior author John Madden, PhD, professor of electrical and computer engineering at UBC. "It could be integrated into wearable devices for biometric monitoring, allowing for real-time visual feedback on vital signs.

"The displays could also be used in robotic skin, enabling robots to display information and interact more intuitively with humans. While there is need for more work to integrate this device into everyday devices, this breakthrough brings us one step closer to a future where flexible and stretchable displays are a common part of our daily lives."

The team's work has been published under open-access terms in the journal Applied Materials & Interfaces, but the researchers have not yet proposed a timescale for bringing the technology to production.