Imagine a digital screen that can bend, twist, and stretch like skin—wrapping smoothly around your wrist, fitting onto medical implants, or even covering robots that move like humans.
Scientists at the University of Chicago Pritzker School of Molecular Engineering have brought that future closer by creating innovative materials that could turn OLED screens into fully stretchable electronics.
OLEDs, or organic light-emitting diodes, power the bright, colorful displays found in smartphones, TVs, laptops, and game consoles.
But today’s OLEDs are rigid. If researchers can make them stretchable, it could unlock a new era of wearable devices, soft medical tools, and lifelike robotic systems.
According to former UChicago researcher Wei Liu, who is now a professor at Soochow University, flexible OLEDs could even serve as light sources for health-monitoring devices that detect conditions like diabetes, heart disease, and cancer.
A few years ago, Associate Professor Sihong Wang’s team created a stretchable light-emitting layer that could be pulled to twice its length while still glowing. But two important components—the cathode and the electron transport layer—remained stiff and fragile, holding back progress.
The new study, published in Nature Materials, solves those final hurdles.
The first breakthrough came from an unexpected idea: making aluminum intentionally brittle. Normally, engineers try to avoid “liquid-metal embrittlement,” a process where certain liquid metals can break solid metals apart.
But the UChicago team realized this “bad” effect could actually help them.
When a special liquid metal touches aluminum, the aluminum cracks into tiny pieces instead of shattering completely.
These tiny cracks act like flexible joints. As the display stretches, the cracks open; when the display relaxes, the cracks close again. Meanwhile, the liquid metal flows into gaps and maintains electrical contact, keeping the device working.
To create this effect in a controlled way, the researchers mixed gallium, indium, and aluminum particles to form a thick, gel-like liquid metal that bonds well to aluminum. This new aluminum gel stayed electrically stable during a full month of tests and can stretch without breaking the circuit.
The second major challenge was the electron transport layer, a delicate but essential part of OLEDs. Electrons need to move smoothly from the cathode into the light-emitting layer, and any barrier can dim the device.
Traditional materials are too brittle to stretch. To fix this, the team developed a new family of polymers built from ring-shaped conductive units connected by flexible chains.
By adjusting how many stretchy chains versus conductive rings the polymer contains, they created a material that is both elastic and efficient at moving electrons.
Together, the new aluminum gel cathode and the flexible polymer transport layer represent a major step toward fully stretchable OLED screens.
Wang and his team hope these advances will eventually lead to commercial products with performance comparable to today’s rigid displays. If successful, stretchable OLEDs could transform how we design electronics, making them softer, smarter, and more compatible with the human body.
