SerpApi.Org
The same class of chemical additive that makes plastic wrap pliable and vinyl flooring soft could be the key to unlocking the next generation of wearable displays. Researchers at the University of Chicago Pritzker School of Molecular Engineering (UChicago PME) have discovered that blending a common plastic softener into light-emitting polymer films makes those films both brighter and more stretchable.
Subscribe to our newsletter for the latest sci-tech news updates.
The work, led by a UChicago PME undergraduate in the class of 2025, offers a surprisingly straightforward solution to one of the central challenges in stretchable OLED technology: making light-emitting materials flexible without reducing how efficiently they emit light.
"In the past, we'd been trying to come up with all kinds of complicated, new chemical structures for stretchable emitters," said Sihong Wang, an associate professor of molecular engineering at UChicago PME and senior author of the new study published in Nature Communications. "But this method is really simple; you just mix two things together, and one of them is a commercially available additive that people have used for decades to soften everyday plastics."
Pushing polymer chains apart
Engineers have long been trying to create stretchable organic light-emitting diodes (OLEDs) for wearable electronics, humanoid robots and 3D displays. For Wang, stretchable OLEDs are one piece of a larger vision: a suite of body-compatible electronics that can sense, compute and communicate directly on or inside the body. His lab has developed stretchable computing patches and biosensors toward that goal, and bright, efficient stretchable displays are a critical component. But balancing brightness and skin-like softness in these materials has been challenging.
Wang's lab has previously worked to develop stretchable TADF (thermally activated delayed fluorescence) polymers, which are far more efficient than conventional emitters. But when these polymers are packed closely together in a film, neighboring units can interfere with each other. Their energies cancel out before any light is released, a phenomenon known as concentration quenching.
Wang and his colleagues suspected that introducing tiny bits of physical space between the polymers could solve this quenching problem. At the same time, physical space between light-emitting polymer chains could allow them to slide past each other more easily under mechanical stretching—just as plasticizers make commodity polymers softer.
To test this idea, undergraduate Glingna Wang turned to dioctyl phthalate (DOP), a plasticizer already widely used in everyday plastics like vinyl.
"Other groups had demonstrated that plasticizers can add some stretchability, but no one had tested the use of plasticizers in light-emitting polymers before," said Glingna Wang.
A simple solution with outsized effects
The results surprised the research team. DOP didn't just make the TADF films more stretchable; it also made them more efficient at fluorescing. The efficiency climbed from 60% for the untreated film to nearly 100%, approaching the theoretical maximum. At the same time, the film's stretchability improved dramatically, from a crack-onset strain of just 5% to more than 110%.
Crucially, the effect was not limited to one polymer. When the team added DOP to four other TADF polymers with different chemical structures, all showed substantial gains in both efficiency and stretchability. That broad applicability is what distinguishes this approach from conventional strategies, which typically require custom chemical synthesis for each new material.
"We found a potentially broadly applicable physical method that could work across different types of polymer-based emitters," said Wang.
In working OLED devices, the plasticized films led to a 35% improvement in efficiency over devices made without DOP.
Led by an undergraduate
Glingna Wang, who is now beginning a Ph.D. degree at Northwestern University, said that when she joined the Wang lab, she didn't expect to become the first author on a paper.
"I wasn't expecting, as an undergrad, to lead an independent project," said Wang. "But with the great trust and guidance of Professor Wang, and the supportive environment in the Wang group, I gradually learned to tackle problems and face actual research issues on my own."
She added that the experience prepared her well for graduate school, where she plans to keep studying biomedical applications of electronics.
At UChicago PME, Wang and colleagues are continuing to incorporate the new emitters into display arrays and are exploring their use in optical therapies and light-based biomedical devices.
More information: Glingna Wang et al, Approaching-unity PLQY and high stretchability in polymer emitters via molecular spacers, Nature Communications (2026). DOI: 10.1038/s41467-026-73223-9
Provided by University of Chicago
This story was originally published on Tech Xplore.
