Dynamic shape-morphing OLED panel with built-in speaker -- all while maintaining ultra-thin flexibility

Overcoming Limitations of Current Flexible Displays

As the display industry rapidly advances toward flexible technologies -- bendable, foldable, rollable, and stretchable -- most implementations still rely on mechanical structures such as hinges, sliders, or motorized arms. While these allow for shape adjustment, they also result in increased thickness, added weight, and limited form factor design. These drawbacks are particularly restrictive for smartphones and wearable electronics, where compactness and eleganceare critical.

Moreover, for immersive user experiences, current devices often require separate speaker modules, further increasing device complexity and volume. The integration of both shape adaptability and audio functionality has remained a significant challenge -- until now. Take bendable displays as a case in point. While they can adjust screen curvature to improve viewing immersion and reduce distortion, most current designs, such as those showcased at MWC 2024, achieve transformation via mechanically forced U-shaped bends. Their flexibility is limited, and they continue to rely on external components for both movement and sound output.

POSTECH's Breakthrough: Shape Transformation and Sound Integration

To overcome these limitations, the POSTECH research team introduced a novel solution based on a specialized ultra-thin piezoelectric polymer actuator. When integrated into a flexible OLED panel, this actuator enables electrically driven shape transformation into a wide variety of complex forms -- not only concave curves, but also convex, S-shaped, inversed S-Shaped and wave-like configurations that respond dynamically, almost like a display in motion.

Crucially, this deformation is achieved entirely through electrical signals, without any mechanical hinges, gears, or external motors. The OLED display maintains its signature thinness, softness, and lightweight profile, achieving new levels of mechanical freedom without any physical burden.

Even more impressively, the same actuator can also generate vibrations in response to high-frequency electrical signals, allowing the OLED panel to function as a speaker. This means the display surface itself emits sound, completely removing the need for traditional speaker hardware.

"This is the first technology to combine freeform shape morphing and built-in sound output in a single ultra-thin OLED panel, without external components," said Professor Choi. "We preserved everything OLEDs are known for -- thinness, flexibility, and lightweight -- and expanded their functionality in a whole new direction of complex and dynamic shape morphing with additonal sound emission."

Demonstrated on Real OLED Panels

The research team successfully implemented this technology on an actual smartphone-scale OLED panel. The panel demonstrated reliable, reversible shape transformation between a variety of geometries and clear sound generation -- all while remaining compact, flexible, and thin.

This first and all-in-one solution contrasts sharply with current commercial displays. For example, LG's CES 2025 award-winning 5K 2K bendable monitor still relies on motorized structural support, and Samsung's AI-enhanced OLEDs showcased at MWC 2024, while impressive, do not integrate audio into the display surface itself and wrapping conventional bulky sepeaker with bendable OLED using structural support as well. POSTECH's approach uniquely merges mechanical adaptability and acoustic output -- fully embedded in the OLED structure itself. As a result, all while maintaining ultra-thin flexibility is achieved in compact size of smartphone.

Implications for Next-Generation Devices

This innovation lays the groundwork for a new generation of intelligent, shape-adaptive, and audio-responsive displays across multiple industries. Potential applications range from morphing mobile displays, immersive automotive dashboards, and audiovisual wearables, to soft robots with interactive, expressive surfaces.

The research was supported by Korea's Ministry of Trade, Industry and Energy (Technology Innovation Program), the LG Display-POSTECH Incubation Collaboration Project, and the National Research Foundation of Korea's BK21 FOUR program.