Researchers build a stretchable OLED that can double in size without dimming
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The evolution of display technology has long chased a moving target: how to achieve full flexibility without sacrificing brightness or performance. Now, a collaboration between Drexel University and Seoul National University has delivered a major advance, building a stretchable OLED that doubles in size while preserving a steady glow and record efficiency.
The breakthrough is based on a class of materials known as MXenes: ultrathin, highly conductive sheets that combine the mechanical resilience of metals with the flexibility of polymers. Co-discovered by Drexel materials scientist Yury Gogotsi, MXenes are layered carbides and nitrides that can deform through bending and sliding between layers rather than fracturing.
Researchers have now demonstrated that when used as the transparent electrode in OLEDs, MXenes outperform the industry’s standard material, indium tin oxide (ITO), in both stretchability and brightness.
Traditional OLEDs rely on a sandwich-like structure of conductive and organic layers that emit light when positive and negative charges meet. The ITO film has served for decades as a stable, transparent anode – until now. Though effective on flat surfaces, ITO is brittle, fracturing under strain and limiting its use in applications that require motion or bending. MXenes solve that problem by forming thin, flexible films only 10 nanometers thick that maintain conductivity as they stretch.
Performance gains were equally striking. The display reached an external quantum efficiency of 17 percent, a measure of how effectively electrical energy converts to visible light, described by experts as a record for intrinsically stretchable OLEDs.
Materials scientist Seunghyup Yoo of KAIST noted that 20 percent efficiency is considered a theoretical ceiling, making this result especially notable.
Beyond the electrode, the Seoul-based team introduced two new organic layers into the OLED structure. One directs positive charge flow efficiently toward the light-emitting region, while the other recycles energy that would otherwise dissipate as heat. Together with the MXene film, these layers sustain high brightness and stability even under mechanical stress.
Besides consumer electronics, potential applications range from industrial displays and soft robotics to wearable health monitors woven into fabric or applied directly to the skin. Gogotsi sees particular promise in medical and diagnostic devices that could show vital signs in real time, outperforming today’s smartwatches and fitness trackers.
Challenges remain before commercialization. According to KAIST’s Yoo and the University of Chicago’s Sihong Wang, who both study stretchable electronic materials, the devices still require improved encapsulation. OLEDs are highly sensitive to oxygen and moisture, and existing barrier technologies typically rely on rigid materials. Developing flexible, durable encapsulation layers will be essential, as will ensuring long-term image uniformity under repeated mechanical stress.
Even so, researchers believe the progress signals a new stage for wearable and embedded electronics. Gogotsi envisions a gradual shift from handheld to integrated displays: from phones and tablets toward clothing, skin patches, and objects with built-in illumination. “Flexible displays can be on the sleeve of your jacket,” he says.
“They can be folded, rolled, or even worn. They can be everywhere.”
