신소재공학과

Research Highlight

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.
These f-VLEDs (thickness: 5 micrometre, size: below 80 micrometre) can be applied to optogenetics for controlling the behavior of neuron cells and brains. In contrast to the electrical stimulation that activates all of the neurons in brain, optogenetics can stimulate specific excitatory or inhibitory neurons within the localized cortical areas of the brain, which facilitates precise analysis, high-resolution mapping, and neuron modulation of animal brains. (Refer to the author's previous ACS Nano paper "Optogenetic Mapping of Functional Connectivity in Freely Moving Mice via Insertable Wrapping Electrode Array Beneath the Skull")

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.


                              이건재 교수 기사 4.jpg


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."
He recently established a startup company (FRONICS Inc.) based on micro LED technology and is looking for global partnerships for commercialization. This result was published in the February 2018 issue of Nano Energy ("Optogenetic Control of Body Movements via Flexible Vertical Light-Emitting Diodes on Brain Surface").

No. Subject Author Date Views
Notice KAIST Develops Sodium Ion Batteries using Copper Sulfide ADMINI 2018.04.24 692
» Researchers develop flexible vertical micro LED ADMINI 2018.02.07 851
Notice Lifespan of Fuel Cells Maximized using Small Amount of Metals ADMINI 2018.01.21 955
Notice A New Spin Current Generating Material Developed ADMINI 2017.12.21 1123
Notice Professor Kim Sang Ouk of KAIST participated in editorship of GRAPHIN NEW MATERIALS ADMINI 2017.10.23 1563
Notice Pd nanowire array-based ultra-fast hydrogen gas sensor by using engineered nanofiltration of metal-organic framework ADMINI 2017.09.27 1713
30 7 nanometer Semiconductor Manufacturing Technology with Camera Flash file ADMINI 2017.09.14 1822
29 Development of disease diagnjosis sensor using animal protein catalyst file ADMINI 2017.07.20 1978
28 Making Graphene Using Laser-induced Phase Separation file ADMINI 2016.12.07 4398
27 Hyper-stretchable elastic piezoelectric energy harvester file ADMINI 2015.04.29 9495
26 “Nature Materials” News & Views wrote by Prof. Sang Ouk Kim file admin 2015.02.17 11543
25 Academic Achievements & Related Awards file admin 2015.02.17 9115
24 Best Paper Award at 2014 Pan Pacific Microelectronic Symposium file admin 2015.02.17 8961
23 The Way towards Commercialization of Highly Efficient Nanogenerator file admin 2015.02.17 9149
22 The First Demonstration of Self-powered Cardiac Pacemaker file admin 2015.02.17 8875
21 Equipment Development: “Hu:u” -New Concept Indoor Environmental Gauge file admin 2015.02.17 5676
20 The Convergence New Technology Fair Silver Award file admin 2015.02.17 3910
19 Grand Prize at the Dow Chemical Korea Award 2014 file admin 2015.02.17 3937
18 Mobile Sensor Array Platform & its Circuit Development. file admin 2015.02.17 4046
17 Intel Best Paper Award at Electronic Components and Technology Conference file admin 2015.02.17 4021