Researchers develop flexible vertical micro LED (w/video)
(Nanowerk News) A Korea Advanced Institute of Science and Technology (KAIST) research team led by Professor Keon Jae Lee from the Department of Materials Science and Engineering and Professor Daesoo Kim from the Department of Biological Sciences has developed flexible vertical micro LEDs (f-VLEDs) using anisotropic conductive film (ACF)-based transfer and interconnection technology. The team also succeeded in controlling animal behavior via optogenetic stimulation of the f-VLEDs.
Flexible micro LEDs have become a strong candidate for the next-generation display due to their ultra-low power consumption, fast response speed, and excellent flexibility. However, the previous micro LED technology had critical issues such as poor device efficiency, low thermal reliability, and the lack of interconnection technology for high-resolution micro LED displays.
The research team has designed new transfer equipment and fabricated a f-VLED array (50x50) using simultaneous transfer and interconnection through the precise alignment of ACF bonding process. These f-VLEDs achieved optical power density (30 mW/mm2) three times higher than that of lateral micro LEDs, improving thermal reliability and lifetime by reducing heat generation within the thin film LEDs.
In this work, they inserted the innovative f-VLEDs into the narrow space between the skull and the brain surface and succeeded in controlling mouse behavior by illuminating motor neurons on two-dimensional cortical areas located deep below the brain surface.
Comparison of micro-LEDs Technology. (IMage: KAIST)
Professor Lee said, "The flexible vertical micro LED can be used in low-power smart watches, mobile displays, and wearable lighting. In addition, these flexible optoelectronic devices are suitable for biomedical applications such as brain science, phototherapeutic treatment, and contact lens biosensors."