(From the left) Research team members of this study: Ph.D. Hyungsoo Yoon, Ph.D. Sujin Jeong of Seoul National University (SNU) Electrical and Computer Engineering (ECE) Department, Prof. Yongtaek Hong of SNU ECE, Prof. Byeongmoon Lee of DGIST.

Professor Yongtaek Hong’s research team of Seoul National University (SNU) department of Electrical and Computer Engineering (ECE) stated that they have developed new technology that connects micro-scale light emitting diodes (micro-LEDs) physically and electrically. Such technology can be applied to flexible & stretchable displays for stretchable electronics and electronic skin.

The core of their “site-selective integration strategy” involves selectively patterning adhesives containing ferromagnetic particles to microdevices, using a dip-transfer coating method, followed by tuning the distribution of ferromagnetic particles by a magnetic field, forming an anisotropic conductive path. The purpose of the strategy is to effectively integrate rigid electronic devices to soft electrodes & substrates.

Current anisotropic conductive films suffer from either rigid morphology that degrades the stretchability and flexibility of electrodes & substrates, or mechanical failure due to the softness of adhesives. The team explains that their method can overcome such challenges in the integration of flexible electronics.

They utilized their strategy to integrate a micro-IC controller unit and a LED display unit onto a flexible printed circuit board (PCB), implementing a miniature wearable display-sensor system smaller than a commercial micro-IC chip.

Their system shows the highest flexibility and stretchability among currently reported micro-LED arrays. Their strategy also enables the integration of a wide range of devices onto any type of electrode including stretchable electrodes, since their technique is appliable regardless of the material properties of substrate and electrode.

Professor Hong stated, "The significance of this study lies in the development of a technology that can systematically integrate high-performance microelectronic devices while maximizing the mechanical properties of flexible and stretchable systems. This will contribute to the commercialization of flexible and stretchable devices in the future."

This research was supported by the Samsung Future Technology Development Program and was published as the cover paper in the May issue of 'Nature Electronics,' the world's leading academic journal in the field of electronics.

(Reporter Yeongho Kim, lloydmind@etnews.com)

Source: https://www.etnews.com/20240606000023

Translated by: Jiyong Yoo, English Editor of the Department of Electrical and Computer Engineering, cyoo7@snu.ac.kr