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OLED breakthrough: Each pixel a sound source

As beautiful as many OLED large-screen TVs are today, they often lack great sound quality without a sound bar. The speakers have been thinned and diminished, and they often point backward or down inside the back of the unit. But what if every OLED pixel was a mini speaker itself?

A research team led by Professor Su Seok Choi of the Department of Electrical Engineering at POSTECH (Pohang University of Science and Technology) in South Korea and PhD candidate Inpyo Hong of the Graduate Program in Semiconductor Materials and Devices has developed the world's first Pixel-Based Local Sound OLED technology. This technology enables each pixel of an OLED display to simultaneously emit different sounds, essentially allowing the display to function as a multichannel speaker array.

The team successfully demonstrated the technology recently on a 13-in. OLED panel, equivalent to those used in laptops and tablets. The research has been published online in the journal Advanced Science.

To improve the sound of ever-thinning displays, the researchers focused on integrating advanced sound capabilities directly into OLED panels, known for their slim, flexible form factors. While companies have explored attaching exciters to the back of TVs or bending OLEDs around speakers -- as seen at MWC 2024 by Samsung and in an OLED panel speaker by LG -- these methods still rely on bulky hardware and face challenges in accurate sound localization.

The core issue is that traditional exciters -- devices that vibrate to produce sound -- are large and heavy, making it difficult to deploy multiple units without interference or compromising the OLED's thin design. Additionally, sound crosstalk between multiple speakers leads to a lack of precise control over localized audio.

The POSTECH team overcame these challenges by embedding ultra-thin piezoelectric exciters within the OLED display frame. These piezo exciters, arranged similarly to pixels, convert electrical signals into sound vibrations without occupying external space. Crucially, they are fully compatible with the thin form factor of OLED panels.

As a result, each pixel can act as an independent sound source, enabling Pixel-Based Local Sound technology. The researchers also developed a method to completely eliminate sound crosstalk, ensuring that multiple sounds from different regions of the display do not interfere with each other, which is something previously unattainable in multichannel setups.

This innovation allows for truly localized sound experiences. For instance, in a car, the driver could hear navigation instructions while the passenger listens to music -- all from the same screen. In virtual reality or smartphones, spatial sound can dynamically adapt to the user's head or hand movements, enhancing realism and immersion.

Most notably, though, for starters, the technology was successfully implemented on the 13-in. OLED panel, proving its practical scalability and commercial viability. The display delivers high-quality audio directly from the screen without the need for external speakers, all while preserving the slim and lightweight benefits of OLED.

"This technology has the potential to become a core feature of next-generation devices, enabling sleek, lightweight designs in smartphones, laptops, and automotive displays -- while delivering immersive, high-fidelity audio," said Professor Choi.

Source: Pohang University of Science and Technology

Published May 2025

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