This new OLED display can be wrapped around your wrist

Researchers have developed OLED displays with extreme flexibility and high performance.
Loukia Papadopoulos
Current OLED screens are not very flexible.jpg
Current OLED screens are not very flexible.

kentoh/iStock 

Researchers have developed new OLED displays that are extremely flexible, so much so that they can be wrapped around a human wrist.

This is according to a press release by the University of Chicago published last week.

“One of the most important components of nearly every consumer electronic we use today is a display, and we’ve combined knowledge from many different fields to create an entirely new display technology,” said Sihong Wang, assistant professor of molecular engineering, who led the research with Juan de Pablo, Liew Family Professor of Molecular Engineering.

“This is the class of material you need to finally be able to develop truly flexible screens,” added de Pablo. “This work is really foundational and I expect it to allow many technologies that we haven’t even thought of yet.”

Today’s OLED displays are great for showcasing screens but don’t offer much leeway in terms of flexibility.

“The materials currently used in these state-of-the-art OLED displays are very brittle; they don’t have any stretchability,” said Wang. “Our goal was to create something that maintained the electroluminescence of OLED but with stretchable polymers.”

And so they did!

“We have been able to develop atomic models of the new polymers of interest and, with these models, we simulated what happens to these molecules when you pull on them and try to bend them,” explained de Pablo. 

“Now that we understand these properties at a molecular level, we have a framework to engineer new materials where flexibility and luminescence are optimized.”

Now the researchers have even more ambitious goals for their work.

“My overall dream is to make all the essential components for a full system of wearable electronics, from sensing to processing to displaying information,” Wang explained. “Having this stretchable light-emitting material is another step toward that dream.”

The team also has plans to add additional colors into the fluorescence of the flexible displays improving their efficiency and performance.

“The goal is to eventually get to the same level of performance that existing commercial technologies have,” concluded Wang in the statement.

The study was published in Nature Materials.

Study abstract:

Stretchable light-emitting materials are the key components for realizing skin-like displays and optical biostimulation. All the stretchable emitters reported to date, to the best of our knowledge, have been based on electroluminescent polymers that only harness singlet excitons, limiting their theoretical quantum yield to 25%. Here we present a design concept for imparting stretchability onto electroluminescent polymers that can harness all the excitons through thermally activated delayed fluorescence, thereby reaching a near-unity theoretical quantum yield. We show that our design strategy of inserting flexible, linear units into a polymer backbone can substantially increase the mechanical stretchability without affecting the underlying electroluminescent processes. As a result, our synthesized polymer achieves a stretchability of 125%, with an external quantum efficiency of 10%. Furthermore, we demonstrate a fully stretchable organic light-emitting diode, confirming that the proposed stretchable thermally activated delayed fluorescence polymers provide a path towards simultaneously achieving desirable electroluminescent and mechanical characteristics, including high efficiency, brightness, switching speed and stretchability as well as low driving voltage.