OLEDs: Shape-morphing panel with built-in speaker; bright stacked microdisplays; graphene-enabled laser lift-off.
Researchers from Pohang University of Science and Technology (POSTECH) developed a flexible OLED panel that can freely transform its shape while simultaneously functioning as a speaker.
The design is based on a based on a specialized ultra-thin piezoelectric polymer actuator that when integrated into a flexible OLED panel enables electrically driven shape transformation into a wide variety of complex forms, including concave, convex, S-shaped, inversed S-shaped, and wave-like curves that respond dynamically. The deformation is achieved entirely through electrical signals, without any mechanical hinges, gears, or external motors.
The same actuator can also generate vibrations in response to high-frequency electrical signals, allowing the OLED panel to emit sound without the need for traditional speaker hardware. The team demonstrated the approach on an actual smartphone-scale OLED panel. [1]
Researchers at the Fraunhofer Institute for Photonic Microsystems IPMS developed OLED stacks that enable monochrome microdisplays with a brightness of over 70,000 Nits. The display could be used in applications that operate in daylight, such as AR glasses.
“By stacking OLED layers, this outstanding brightness was achieved. The individual OLED units are ‘series connected’, which increases the brightness with each additional unit without raising the current density in the component. This can be utilized to either achieve extremely high brightness or, at a given brightness, to significantly reduce the current density that determines lifetime. Measurements have shown that when comparing a 1-unit and a 2-unit OLED, the lifetime LT95, i.e., the drop in brightness by 5%, at 50,000 Nits can be significantly improved from 900 to 1300 hours,” said Johannes Zeltner, a PhD student at Fraunhofer IPMS, in a statement.
The current efficiency and brightness of 1-, 2-, and 3-fold stacked OLEDs were initially evaluated on passive test substrates and were subsequently successfully transferred to 0.62-inch CMOS backplanes with SXGA resolution. [2]
Researchers from Seoul National University of Science and Technology (SEOULTECH), Korea Advanced Institute of Science and Technology (KAIST), and Korea Institute of Machinery and Materials developed a graphene-enabled enhanced laser lift-off (GLLO) technique that prevents damage while separating ultrathin OLED displays.
The GLLO method integrates a layer of chemical vapor deposition-grown graphene between the polyimide (PI) film and its glass carrier. With the method, the researchers successfully separated 2.9 μm thick ultrathin PI substrates without any mechanical damage or carbon residue left behind.
“Graphene’s unique properties, such as its ability to absorb ultra-violet (UV) light and distribute heat laterally, enable us to lift off thin substrates cleanly, without leaving wrinkles or residues,” said Sumin Kang, a professor at SEOULTECH.
OLEDs processed with GLLO retained their electrical and mechanical performance, showing consistent current density-voltage-luminance properties before and after lift-off. These devices also withstood extreme deformations, such as folding and twisting, without functional degradation. [3]
[1] Park, J.Y., Shin, J.H., Hong, I.P. et al. Dynamic bendable display with sound integration using asymmetric strain control of actuators with flexible OLED. npj Flex Electron 9, 24 (2025). https://doi.org/10.1038/s41528-025-00396-6
[2] Zeltner, J. Multiple stacked monochrome OLEDs for high-brightness micro-display applications. SPIE AR VR MR 2025. https://spie.org/ar-vr-mr/presentation/Multiple-stacked-monochrome-OLEDs-for-high-brightness-micro-display-applications/13414-54
[3] Kang, S., Chang, J., Lim, J. et al. Graphene-enabled laser lift-off for ultrathin displays. Nat Commun 15, 8288 (2024). https://doi.org/10.1038/s41467-024-52661-3
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