"Maintaining High Resolution Even When Stretched" Core Technology Developed for Stretchable Displays

A core technology for stretchable displays that operate even when the screen is pulled has been developed. Following the evolution from flat to curved monitors and foldable phone screens, this suggests the possibility of further advancement in display technology.

On the 11th, KAIST announced that a research team led by Professor Seunghyup Yoo of the Department of Electrical Engineering collaborated with Professor Han-eol Moon of Dong-A University and the Reality Device Research Division of the Electronics and Telecommunications Research Institute (ETRI) to successfully implement a stretchable organic light-emitting diode (OLED) display.

(From left) Professor Yoo Seung-hyup, KAIST; Dr. Lee Dong-gyun, KAIST; Professor Moon Han-eol, Dong-A University. Courtesy of KAIST

The technology developed by the joint research team involves creating an ultra-thin flexible OLED and hiding part of its light-emitting area between two adjacent isolated regions, thereby securing both stretchability and high luminance density simultaneously.

The hidden light-emitting area gradually reveals itself during stretching, compensating for the reduction in the light-emitting area ratio.

Through this, the joint research team emphasized that they were able to achieve world-class light-emitting area ratios while maintaining almost no reduction in resolution even when the display is stretched or pulled.

Existing stretchable displays typically secure performance by using fixed, rigid light-emitting parts and achieve stretchability through bent-shaped connecting parts.

In this case, the bent-shaped connecting parts that do not emit light cause a low ratio of light-emitting area to the total area. Especially, as the bent-shaped connecting parts expand during stretching, the light-emitting area ratio decreases even further, which was a prominent issue.

A comparison of the limitations in reducing the luminous area ratio of existing stretchable display technologies and the method by which the research team’s proposed technology overcomes these limitations. Provided by KAIST

In contrast, the joint research team achieved a near 100% light-emitting area ratio before stretching with the proposed structure. They also implemented a platform where the light-emitting area ratio decreases by only 10% even after 30% system stretching.

This contrasts with existing platforms, which show a high light-emitting area ratio reduction of about 60% under the same deformation conditions. Above all, the platform developed by the joint research team demonstrated mechanical stability that operates robustly under repeated operations and various external force conditions.

In particular, it can operate stably on curved surfaces such as spherical objects, cylinders, and human body parts, confirming its applicability for wearable devices and light sources attachable to free-form surfaces that can accommodate balloon expansion or joint movements, as well as the possibility of future displays that compensate for resolution loss during stretching, the joint research team introduced.

Professor Seunghyup Yoo of KAIST said, “We already live in an era where displays that are not flat, such as foldable phones and curved monitors, are easily accessible. Furthermore, the form of displays will become more diverse, expanding into stretchable display technology that operates even when the screen is stretched.”

He added, “The joint research team proposed a solution to overcome the challenges of existing stretchable displays and hopes to act as a catalyst to accelerate the commercialization of stretchable displays.”

Meanwhile, this research was conducted with support from the National Research Foundation of Korea’s Leading Research Center Project (Human-Attachable Light Therapy Engineering Research Center) and the Electronics and Telecommunications Research Institute’s research operation fund project (ICT Materials, Components, and Equipment Independence and Challenging Technology Development).

This content was produced with the assistance of AI translation services.