Scientists have developed a thin, flexible display that can shine several times brighter than a typical smartphone screen while using relatively little power.
The technology could eventually lead to glowing health patches worn on the skin, underwater displays and smart surfaces for robots.
The breakthrough comes from researchers led by Assistant Professor Tan Yu Jun at the National University of Singapore, working with scientists from Singapore’s Agency for Science, Technology and Research.
Their study was published in Science Advances.
Flexible displays already exist, but current technologies have important limitations. Organic light-emitting diode, or OLED, screens contain multiple layers that can make them difficult to bend repeatedly without damage.
Other flexible light-producing technologies can require hundreds or even thousands of volts, making them unsuitable for wearable devices.
The researchers instead focused on electrochemiluminescent, or ECL, devices.
ECL produces light through chemical reactions triggered by electricity. A liquid containing light-emitting molecules is placed between two electrodes. When electricity passes through the device, the molecules undergo reactions that release energy as visible light.
The principle is somewhat similar to bioluminescence, which allows animals such as fireflies and some deep-sea creatures to glow. The difference is that ECL uses electricity to trigger the light-producing reaction.
ECL devices can be thin, flexible and energy-efficient. Until now, however, they have generally been too dim and unstable for practical displays.
The Singapore team tackled both problems by changing the liquid inside the device and redesigning its electrodes.
Traditional ECL devices use an ionic liquid containing relatively large ions that can slow the movement of electrical charge. The researchers switched to a different liquid containing smaller, more mobile ions. This allowed electrical reactions to occur more efficiently while also helping more light-emitting material dissolve in the liquid.
They then redesigned the electrodes. Instead of using two identical transparent electrodes, they combined a textured electrode that improves chemical reactions with a smooth electrode that allows more light to pass through. A thin silver mirror was added behind the device to reflect escaping light toward the viewer.
Together, these changes dramatically increased performance.
The new device reached a brightness of 1,552 candelas per square meter. According to the researchers, that’s roughly three to four times brighter than a typical smartphone screen used indoors and more than three times brighter than the best conventional ECL devices.
The displays also lasted much longer. During continuous operation, the improved device produced light for about two hours, compared with only 29 minutes for the older design.
To demonstrate possible applications, the researchers created several prototypes.
One was a flexible skin patch that used different colors to show readings from a sweat glucose sensor, potentially allowing people to see information directly on their skin without checking another device.
They also built a simple digital display capable of repeatedly showing changing numbers and created a flexible version that continued glowing while completely submerged in water.
The team is now working to improve colors such as blue and green and develop displays that can stretch and even repair themselves after damage.
Eventually, the technology could turn skin, clothing, robots and underwater equipment into soft, lightweight visual displays—bringing digital information to surfaces where conventional screens simply don’t work.
