The Korea Institute of Machinery and Materials (President Sang Jin Park, hereafter referred to as KIMM), an institute under the jurisdiction of the Ministry of Science and ICT, has successfully developed a new stretchable meta-display technology that can be stretched up to 25% without image distortion, for the first time in the world.
Senior researcher Dr. Bongkyun Jang and his research group members of the Department of Nano-Mechanics at KIMM have recently developed a distortion-free stretchable meta-display under the uniaxial stretching, and published their research results in the peer-reviewed journal Advanced Functional Materials.
* Paper Title: Auxetic Meta-display: Stretchable Display without Image Distortion (published online on Feb. 15, 2022)
This achievement was developed through the "Development of Meta-display Technology Based on Micro-LEDs " project carried out in 2019 as part of the Ministry of Science and ICT's Global Frontier Project, with support from the Center for Advanced Meta-Materials (Director Dr. Hak-Joo Lee, hereinafter referred to as CAMM). The Department of Nano-Mechanics at KIMM has been researching the field of micro-LED transfer technology since 2008.
For the first time in the world, the KIMM research team successfully developed a 3-inch micro-LED meta-display that does not distort the displayed image, even when the display is pulled in a given direction. This was achieved by using the design and manufacturing technology of metamaterials with unique mechanical properties that do not exist in nature.
Most stretchable materials in nature, such as rubber, demonstrate the shrinkage in width when stretched lengthwise and thus resulting in image distortion. This was also the same in cases of the rubber-based stretchable display, up until now.
The KIMM research team applied mechanical metamaterials with a negative Poisson's ratio to a circuit board. The Poisson's ratio refers to the ratio at which the width of material shrinks when it is stretched lengthwise. When a mechanical metamaterial with a Poisson's ratio of -1 is stretched lengthwise, it demonstrates the effect of stretching at the same ratio widthwise. Thus, a display using such materials is characterized by images that are not distorted.
In developing this new meta-display manufacturing technology, the team applied mechanical metamaterial designs and manufacturing technology to the world's leading large-area micro-LED roll transfer technology. Based on the successful results of this project, the research team plans to conduct follow-up research on micro-LED displays for ultra-realistic metaverses.
Furthermore, in order to respond to the growing mini-LED and graphene industries, the team has established research institute spin-off company, YTS Micro-Tech and MCK-Tech, to promote the practical use of these new technologies.
Dr. Bongkyun Jang stated that his team has solved the fundamental issue of image distortion in stretchable displays by using meta-structures, and he and his team will continue to pursue the commercialization of meta-display technologies, so that they can be applied to various electronic products in the future.
The newly developed flexible meta-display technology is expected to contribute to the diversification of platforms for mobile electronic devices, such as mobile phones and tablets. Such displays can also adhere to the skin of the human body without any wrinkles, thus allowing possibilities for its application in the field of medical devices, beauty and healthcare.
