Electrically driven shape shifting OLED display

Researchers in South Korea have developed a groundbreaking technology in the form of a smartphone-sized OLED display that can change its shape and double up as a speaker, thanks to a piezoelectric actuator. The team at the Pohang University of Science and Technology (POSTECH) utilized asymmetrical strain engineering on poly(vinylidene fluoride) (PVDF) with a piezoelectric polymer actuator to achieve bidirectional and complex deformations through electrical signals, eliminating the need for mechanical hinges or external motors.

While most bendable, foldable, rollable, and stretchable displays currently in the market rely on mechanical structures like hinges, sliders, or motorized arms for shape adjustment, these components often lead to increased thickness, added weight, and limited flexibility in the design of the form factor. These limitations are particularly challenging for smartphones and wearable electronics.

• Stretchable display expands by 50%
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Integrated into a flexible OLED panel, the PVDF actuator leverages polarization and applied electric field to drive a variety of complex forms, including concave curves, convex shapes, S-shaped configurations, inversed S-shaped designs, and wave-like patterns that dynamically respond, almost like a display in motion.

Moreover, the same actuator has the capability to produce vibrations in response to high-frequency electrical signals, enabling the OLED panel to function as a speaker. This innovative feature means that the display surface itself can emit sound, eliminating the need for traditional speaker hardware.

Professor Su Seok Choi from the Department of Electrical Engineering expressed, “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 have retained all the key characteristics OLEDs are known for—thinness, flexibility, and lightweight—while expanding their functionality in a completely new direction of complex and dynamic shape morphing with additional sound emission.”

The potential applications of this cutting-edge technology are vast, ranging from morphing mobile displays and immersive automotive dashboards to audiovisual wearables and soft robots with interactive and expressive surfaces. The development opens up exciting possibilities for the future of display and audio technologies, promising a new era of innovation and user experience enhancement.