Scientists unveil flexible OLED panel with built-in speaker

Researchers from Pohang University of Science and Technology (POSTECH) have developed a smartphone-type OLED panel that can transform its shape while functioning as a speaker, without sacrificing its ultra-thin and flexible properties. This study, led by Professor Su Seok Choi from the Department of Electrical Engineering, was published in the journal npj Flexible Electronics.

The OLED panel developed by POSTECH is based on a specialised ultra-thin piezoelectric polymer actuator. When integrated into a flexible OLED panel, this actuator enables electrically driven shape transformation into a variety of complex forms — not only concave curves, but also convex, S-shaped, inverse S-shaped and wave-like configurations that respond dynamically, almost like a display in motion.

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

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, thereby 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. We preserved everything OLEDs are known for — thinness and flexibility — and expanded their functionality in a whole new direction of complex and dynamic shape morphing with additional sound emission,” Choi said.

The researchers also implemented this technology on a 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 solution contrasts with current displays, as it merges mechanical adaptability and acoustic output, which are fully embedded in the OLED structure itself.

The OLED panel 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 audio-visual wearables, to soft robots with interactive, expressive surfaces.

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