Think of a wearable patch that aids in tracking vital signs via changes in color displays or shipping labels that illuminate to show changes in the temperature or sterility of food items.
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These come under the possible uses for a new flexible display made by scientists from the University of British Columbia (UBC), announced recently in the journal ACS Applied Materials and Interfaces.
This device is capable of fast, real-time, and reversible color change. It can stretch up to 30 per cent without losing performance. It uses a color-changing technology that can be used for visual monitoring. And it is relatively cheap to manufacture.
Claire Preston, Researcher, University of British Columbia
Preston developed the device as part of her master’s in electrical and computer engineering.
Earlier attempts to make stretchable displays have involved complicated designs and materials, thereby restricting their optical quality and stretchability. In this new study, researchers leaned on electrochromic displays—which can change color reversibly while needing low power consumption—for such limitations to be defeated.
“We used PEDOT: PSS, an electrochromic material that consists of a conductive polymer combined with an ionic liquid, resulting in a stretchable electrode that acts as both the electrochromic element and the ion storage layer. This simplifies the device's architecture and eliminates the need for a separate stretchable conductor,” States Ms. Preston.
The display looks transparent and feels like a firm rubber band. To assist the thin layers of PEDOT and enable them to lengthen without breaking, the research group added a stretchable encapsulation material and a solid polymer electrolyte known as styrene-ethylene-butylene-styrene (SEBS).
The potential uses for this stretchable display are significant. 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.
Dr. John Madden, Study Senior Author and Professor of Electrical and Computer Engineering, University of British Columbia
Madden supervised the work.
Furthermore, the profitability of low power consumption and affordability of this technology make it appealing for use in disposable applications like indicator patches used for medical purposes or smart packaging labels for sensitive shipments. Also, it could be utilized to actively alter the color of hats, jackets, and other garments.
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.
Dr. John Madden, Study Senior Author and Professor of Electrical and Computer Engineering, University of British Columbia
Journal Reference
Preston, C., et al. (2023) Intrinsically Stretchable Integrated Passive Matrix Electrochromic Display Using PEDOT: PSS Ionic Liquid Composite. ACS Applied Materials Interfaces. doi.org/10.1021/acsami.3c02902.