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A KAIST research team develops a washable, transparent, and flexible OLED with MXene nanotechnology
Transparent and flexible displays, which have received a lot of attention in various fields including automobile displays, bio-healthcare, military, and fashion, are in fact known to break easily when experiencing small deformations. To solve this problem, active research is being conducted on many transparent and flexible conductive materials such as carbon nanotubes, graphene, silver nanowires, and conductive polymers.
On June 13, a joint research team led by Professor Kyung Cheol Choi from the KAIST School of Electrical Engineering and Dr. Yonghee Lee from the National Nano Fab Center (NNFC) announced the successful development of a water-resistant, transparent, and flexible OLED using MXene nanotechnology. The material can emit and transmit light even when exposed to water.
MXene is a 2D material with high electrical conductivity and optical transmittance, and it can be produced on a large scale through solution processes. However, despite these attractive properties, MXene’s applications were limited as a long-term electrical device due to its electrical properties being degraded easily by atmospheric moisture and water. The material was therefore unable to be systemized into the form of a matrix that can display information.
Professor Choi’s research team used an encapsulation tactic that can protect materials from oxidation caused by moisture and oxygen to develop a MXene-based OLED with a long lifespan and high stability against external environmental factors. The research team first focused on analyzing the degradation mechanism of MXene’s electrical conductivity, and then concentrated on designing an encapsulation membrane. The team blocked moisture and provided flexibility through residual stress offset, ultimately producing a double-layered encapsulation membrane. In addition, a thin plastic film with a thickness of a few micrometers was attached to the top layer to allow washing in water without degradation.
< Figure 1. (a) Transparent passive-matrix display made of MXene-based OLED, (b) Cross-sectional image of MXene-based OLED observed by transmission electron microscope (TEM), (c) Electro-optical characteristic graph of red, green, and blue MXene-based OLED >
Through this study, the research team developed a MXene-based red(R)/green(G)/blue(B) OLED that emits a brightness of over 1,000 cd/m2 that is detectable by the naked eye even under sunlight, thereby meeting the conditions for outdoor displays. As for the red MXene-based OLED, the researchers confirmed a standby storage life of 2,000 hours (under 70% luminescence), a standby operation life of 1,500 hours (under 60% luminescence), and a flexibility withstanding 1,000 cycles under a low curvature of under 1.5mm. In addition, they showed that its performance was maintained even after six hours of immersion under water (under 80% luminescence). Furthermore, a patterning technique was used to produce the MXene-based OLED in the form of a passive matrix, and the team demonstrated its use as a transparent display by displaying letters and shapes.
Ph.D. candidate So Yeong Jeong, who led this study, said, “To improve the reliability of MXene OLED, we focused on producing an adequate encapsulation structure and a suitable process design.” She added, “By producing a matrix-type MXene OLED and displaying simple letters and shapes, we have laid the foundations for MXene’s application in the field of transparent displays.”
< Image 1. Cover of ACS Nano Front Cover (Conceptual diagram of MXene-based OLED display) >
Professor Choi said, “This research will become the guideline for applying MXene in electrical devices, but we expect for it to also be applied in other fields that require flexible and transparent displays like automobiles, fashion, and functional clothing. And to widen the gap with China’s OLED technology, these new OLED convergence technologies must continue to be developed.”
This research was supported by the National Research Foundation of Korea and funded by the Ministry of Science and ICT, Korea. It was published as a front cover story of ACS Nano under the title, “Highly Air-Stable, Flexible, and Water-Resistive 2D Titanium Carbide MXene-Based RGB Organic Light-Emitting Diode Displays for Transparent Free-Form Electronics” on June 13.
2023.07.10 View 3929 -
CXL-Based Memory Disaggregation Technology Opens Up a New Direction for Big Data Solution Frameworks
A KAIST team’s compute express link (CXL) provides new insights on memory disaggregation and ensures direct access and high-performance capabilities
A team from the Computer Architecture and Memory Systems Laboratory (CAMEL) at KAIST presented a new compute express link (CXL) solution whose directly accessible, and high-performance memory disaggregation opens new directions for big data memory processing. Professor Myoungsoo Jung said the team’s technology significantly improves performance compared to existing remote direct memory access (RDMA)-based memory disaggregation.
CXL is a peripheral component interconnect-express (PCIe)-based new dynamic multi-protocol made for efficiently utilizing memory devices and accelerators. Many enterprise data centers and memory vendors are paying attention to it as the next-generation multi-protocol for the era of big data.
Emerging big data applications such as machine learning, graph analytics, and in-memory databases require large memory capacities. However, scaling out the memory capacity via a prior memory interface like double data rate (DDR) is limited by the number of the central processing units (CPUs) and memory controllers. Therefore, memory disaggregation, which allows connecting a host to another host’s memory or memory nodes, has appeared.
RDMA is a way that a host can directly access another host’s memory via InfiniBand, the commonly used network protocol in data centers. Nowadays, most existing memory disaggregation technologies employ RDMA to get a large memory capacity. As a result, a host can share another host’s memory by transferring the data between local and remote memory.
Although RDMA-based memory disaggregation provides a large memory capacity to a host, two critical problems exist. First, scaling out the memory still needs an extra CPU to be added. Since passive memory such as dynamic random-access memory (DRAM), cannot operate by itself, it should be controlled by the CPU. Second, redundant data copies and software fabric interventions for RDMA-based memory disaggregation cause longer access latency. For example, remote memory access latency in RDMA-based memory disaggregation is multiple orders of magnitude longer than local memory access.
To address these issues, Professor Jung’s team developed the CXL-based memory disaggregation framework, including CXL-enabled customized CPUs, CXL devices, CXL switches, and CXL-aware operating system modules. The team’s CXL device is a pure passive and directly accessible memory node that contains multiple DRAM dual inline memory modules (DIMMs) and a CXL memory controller. Since the CXL memory controller supports the memory in the CXL device, a host can utilize the memory node without processor or software intervention. The team’s CXL switch enables scaling out a host’s memory capacity by hierarchically connecting multiple CXL devices to the CXL switch allowing more than hundreds of devices. Atop the switches and devices, the team’s CXL-enabled operating system removes redundant data copy and protocol conversion exhibited by conventional RDMA, which can significantly decrease access latency to the memory nodes.
In a test comparing loading 64B (cacheline) data from memory pooling devices, CXL-based memory disaggregation showed 8.2 times higher data load performance than RDMA-based memory disaggregation and even similar performance to local DRAM memory. In the team’s evaluations for a big data benchmark such as a machine learning-based test, CXL-based memory disaggregation technology also showed a maximum of 3.7 times higher performance than prior RDMA-based memory disaggregation technologies.
“Escaping from the conventional RDMA-based memory disaggregation, our CXL-based memory disaggregation framework can provide high scalability and performance for diverse datacenters and cloud service infrastructures,” said Professor Jung. He went on to stress, “Our CXL-based memory disaggregation research will bring about a new paradigm for memory solutions that will lead the era of big data.”
-Profile: Professor Myoungsoo Jung Computer Architecture and Memory Systems Laboratory (CAMEL)http://camelab.org School of Electrical EngineeringKAIST
2022.03.16 View 19604 -
KAIST Celebrates 50-Year Anniversary with 2,712 New Graduates via 2021 Commencement Ceremony
KAIST is proud to announce the graduation of 2,712 students, including 668 PhDs and 1,331 master’s degree recipients. The pandemic could not stop the university from recognizing each graduate's remarkable and original achievements. A pandemic-proof blended commencement ceremony was held on Friday, February 19, and livestreamed to the graduates and their loved ones.
KAIST decided to take extra precautions to protect graduates and other attendees’ health and well-being.
For the virtual ceremony, only 83 out of the 2,712 graduates were invited to attend the ceremony in person. Graduates were divided into four groups to attend at four different places in Daejeon and Seoul campuses and watch the ceremony via Zoom. No family members or friends of the graduates were allowed to participate at the campus, but happily cheered the graduates via YouTube.
This year’s valedictorian, Hyun-Young Park from the School of Electrical Engineering, received the Award of the Minister of Science and ICT. Salutorian Yeh-Lin Cho from the Department of Materials Science and Engineering received the Award of the KAIST Board of Trustees, while the recipient of the KAIST Presidential Award was Min-Jae Kim from the Department of Bio and Brain Engineering. The Award of the KAIST Development Foundation Chairman and the KAIST Alumni Association Presidential Award were conferred to Kyung-Tae Kim from the Department of Physics and Min-Woo Jung from the Department of Civil and Environmental Engineering, respectively.
President Sung-Chul Shin, Chairman of the Board of Trustees Woo Sik Kim, and a very limited number of faculty members and administrative staff officiated the commencement ceremony from the KAIST Auditorium.
President Shin applauded the graduates’ hard work and dedication in his commencement speech. He also delivered a very special congratulatory message to the bachelor’s degree awardees.
“This year’s commencement is especially meaningful for me. I was appointed as the 16th president of KAIST on February 23, 2017, and met you for the first time on February 28 at the matriculation ceremony. We promised each other—as freshmen and as the first alumnus president—to do our best for the next four years,” President Shin recalled.
He added, “I have done my best to keep my promise, and now my term will end on February 22. Of course, the past four years were even more precious because you were all a part of it.”
In conclusion, President Shin said, “I am proud of you for keeping your end of the promise. Thank you for becoming who you are today. I have high hopes for the bright future that you will be shaping for KAIST and our society.”
The livestream ceremony is archived for viewing on KAIST's Official YouTube Channel.
(END)
2021.02.19 View 7439 -
Virtual Commencement Ceremony Honors the Class of 2020
The KAIST community gathered online to celebrate the 2020 graduating class. The blended ceremony conferred their hard-earned degrees on August 28. The belated celebration, which was postponed from February 21 due to the COVID-19 outbreak, honored the 2846 graduates with live streaming on YouTube beginning at 2:00 pm. The graduates include 721 PhDs and 1399 master’s degree holders.
The government raised its social distancing guidelines to level two out of three on August 23 as the second wave of the virus hit the nation. Level two guidelines prohibit the gathering of more than 50 persons indoors or 100 persons outdoors.
For the virtual ceremony, the Office of Student Affairs and Policy announced a list of 67 graduates who signed up to participate in the graduation ceremony. Graduates were divided into three groups to attend at three different places and watch the ceremony via Zoom. No family and friends of the graduates were allowed to participate at the campus.
This year’s valedictorian, Kon-Yong Lee from the Department of Chemical and Biomolecular Engineering, received the Award of Minister of Science and Technology. Salutorian Hee-Kwang Roh from the Department of Chemistry received the Award of the KAIST Board of Trustees, while the recipient of the KAIST Presidential Award was Hong Jae-Min from the School of Computing.
President Sung-Chul Shin, Chairman of the Board of Trustees Woo-Sik Kim, former Minister of Science and Technology and former Provost at KAIST Dr. KunMo Chung, and a very limited number of faculty and staff members officiated the commencement ceremony from the KAIST auditorium.
President Shin in his commencement speech applauded the graduates’ hard work and dedication and delivered a very special congratulatory message to them. He encouraged the new graduates to be courageous enough to deal with these new challenges as well as future uncertainties, during the greatest transformation brought about by COVID-19.
“Instead of following behind others as a fast follower, we should take the initiative and walk down new paths as a first mover.” He also stressed, “We can transform this crisis into an opportunity by practicing the C3 values KAIST pursues: Challenging, Creating, and Caring.”
As new alumni of Korea’s top science and technology university, he said, “Our graduates should focus on creating the world’s best, first, or only one in their research or their work.” However, he also pointed out the importance of a caring mind for others when working together.
At the ceremony, KAIST conferred an honorary doctorate degree to Dr. Younghoon David Kim, CEO and Chairman of Daesung Group, in recognition of his lifetime dedication to making innovations in the energy industry.
Daesung Group is a leading energy company in Korea which manufactures and supplies natural gas for industries and home users. Dr. Kim is committed to making efficient energy sources by advancing cutting-energy sciences and disruptive technologies. He has served as chairman of the World Energy Council since 2016.
In his acceptance speech, Kim stressed the Grand Energy Transition as a new driving force in the future energy industry for maximizing energy efficiency.
“Since energy is the most basic foundation for all industries, improvements in energy efficiency translate into benefits for all related industries in terms of its efficiency and productivity.”
“The Grand Energy Transition is progressing widely and rapidly across the entire value chain of energy production, distribution, and consumption with decarbonization, decentralization, and digitalization serving as its driving force.”
He went on, “We should regard energy efficiency not as the fifth fuel but the first primary fuel.”
(END)
2020.08.28 View 9719 -
President Lee Myung-bak's Congratulatory Address at 2009 KAIST Commencement Ceremony
Following is the full text of President Lee Myung-bak"s congratulatory address at the 2009 KAIST Commencement Ceremony.
Beloved graduates, proud parents, dear family members,
Mr. Cho Jeong-nam, Chairman of the Board of Directors,
Dr. Suh Nam-pyo, President of KAIST,
Esteemed faculty and staff members, Distinguished guests, ladies and gentlemen,
It is great to see you all.
First of all, I must begin by extending my most sincere congratulations to the 1,976 graduates who are receiving their degrees today. You worked hard, you earned it and I congratulate you.
We must also remember your parents who worked just as hard as you did, if not more, to support you. You may have family members whom you wish to thank for their support and understanding. I also thank and congratulate the faculty and staff members who worked hard to provide the best possible education for you.
Today is also a great day since we can all join together to recognize the achievements of Dr. Ryu Geun-chul and show him how deeply we respect and appreciate his generous contributions to KAIST. Today, Dr. Ryu received an honorary doctorate in science for his life-long contributions in the field of Korean traditional medicine. He has also donated a vast portion of his personal wealth to KAIST for educating future leaders in science and technology.
Dear graduates, faculty members,
KAIST has been in the forefront of leading Korea’s development over the last thirty-eight years. As the preeminent institution devoted to educating the very best minds in science and technology, more than 20% of all doctorate degree holders in Korea’s science and engineering field are KAIST alumnus. KAIST has led the drive to create more than 470 venture start-ups, opening up a vast new horizon for Korea’s scientific and technological breakthrough while leading the economic growth of Korea.
KAIST has done exceptionally well even compared to the world’s best. It is ranked 34th in engineering and IT. It is ranked 46th in natural sciences. These rankings are a demonstration that KAIST is a research-focused institution with global competitiveness.
Moreover, KAIST has been an example for other higher institutions seeking to reform the way colleges and universities operate. KAIST has demonstrated its forward-looking and reform-minded vision in terms of selecting students, recruiting and evaluating professors and managing its courses. In particular, when KAIST selects its students, it doesn’t look only at their test scores but looks for creative and innovative minds with real character and potential. Such practices are having positive influences on how other universities and colleges select their students. Furthermore, KAIST has taken the lead in applying their research skills to matters of global concern through its EEWS initiative. I am proud of such visionary work and will continue to have high hopes for KAIST.
Our promising future depends on gifted individuals and gifted individuals are nurtured through solid education. For a country such as Korea with no natural resources, human capital is our greatest and most precious resource. We must overcome our lack of natural resources with our abundant and limitless brain power.
The 21st century will be a knowledge-based society and so national competitiveness of individual countries will be determined by how competitive its universities and research institutes are. And the time calls for universities with world-class capabilities in research. Especially, our investments in science and technology today will ensure a brighter tomorrow.
I assure you that this government will spare no effort to KAIST so that it can continue to foster the best minds for even greater achievements.
My dear graduates and professors, proud parents and family members,
All of us are going through difficult times due to the global economic crisis. At the same time, we must face global climate change which is our common concern. And this global concern must not be put aside or given less priority because of the economic crisis. We must do all we can to overcome the economic crisis while aggressively and consistently implementing measures to deal with climate change. At the same time, we must continue our quest to develop the next-generation engines of growth in preparation for the future when this economic crisis is eventually over. This is killing three birds with one stone and this is the core of my Low Carbon/Green Growth vision for Korea’s future.
For a country like Korea with no oil reserves whatsoever, Low Carbon/Green Growth is a must. We simply do not have any other choice. It is also the path that the global community must take.
Korea was late in joining the club of industrialized countries but we are ahead in the information technology sector. But, because we did not possess the core technologies in information and communication, we were unable to fully benefit from being ahead.
Now, we must excel in all areas in the age of green growth. Korea’s future growth will depend on how many core technologies we manage to accrue in green technology, such as technologies to conserve energy, development of new and renewable energy. The government will double, compared to last year, its investments into research and development of green technology.
The government has a long-term vision and this vision calls for continuously increasing strategic investments into the new engines of growth and they include basic sciences, core technologies and big science. Deregulation will continue so that we can foster scientific and technological advancements and also attract more investments and people from abroad.
Dear graduates,
Another source of our new engine of growth and our green technology is none other than fusion technology. Our bio, IT and nano technology will come together, and coupled with what is already a world-class IT industry, we can create future engines of growth.
President Suh Nam-pyo stressed that “Inter-disciplinary study that takes place amidst the boundaries of different disciplines is where new discoveries and added-value are found.” This is a reminder of the importance of fusion research. And we all know that KAIST is the leader in this endeavor.
Fusion technology will greatly improve our quality of life and introduce new and innovative ways to solve our real concerns. Healthcare and medical science are just two examples. As our society becomes an aged society, identifying the causes of and finding the cure for degenerative diseases such as Pakinson’s and dementia are becoming more and more important. If we manage to successfully combine our knowledge in medicine, science and engineering, we can come up with revolutionary ways to detect and cure these and other diseases.
In particular, we will soon see science and medicine come together to create an entirely new paradigm in how we take care of our health. Medicinal research and high-tech research hospitals will be the norm. I truly believe that we can save both this planet as well as ourselves by utilizing green technologies and high-tech fusion technology. The government will continue to support such efforts.
Dear graduates, the heroes of today,
Some of you may wish to pursue higher degrees in order to reach even loftier academic goals. Some of you may opt to venture into society.
Wherever you go and whatever you decide to do, do not be afraid of failure. Pursue your dreams. Face the challenges that come your way. And when you boldly face these challenges with the most precious gift you have, your youth and ideals, your dream will come true. Remember that history is made by those who take up the challenge. Do not be discouraged if you fail today. Just pick yourselves up tomorrow and try again. And again.
Do not be consumed by selfish ambitions. But instead, always think what you can do for your society, your country and for humankind.
Science and technology that is used for personal gains or new innovations and technologies lacking even the very basic ethical standards can become a curse to mankind. This is why those aspiring to become scientists and engineers must first agonize over how they plan to better the lives of man before they learn how to conduct experiments. Once you’ve gone through this, you will then be eligible to become true leaders, with your character and technological know-how.
Remember the time you spent hunched over a book, in the classroom, in the library or in laboratories. Do not forget why you came here in the first place. Aim for higher goals in your respective fields.
With that, I wish you a wondrous and exciting new journey.
Again, congratulations and well done!
Thank you.
2009.03.13 View 13384 -
Prof. Chung To Make a Keynote Address at Overseas Seminar
Prof. Chung To Make a Keynote Address at Overseas Seminar
“Instilling Korea’s design promotion policies into Chile”Prof. Kyung-Won Chung will make a keynote address at a design policy seminar in Chile
Prof. Kyung-Won Chung, Department of Industrial Design, will make a keynote address at a seminar named ‘public policies for design industries’, which will be held at Santiago, Chile, July 24 -25.
In the lecture entitled ‘The development model of public policies for design promotion ? Korea’s experiences’, Prof. Chung will present the relationship between national economic development policy and design industry promotion strategy with some real case studies.
The seminar co-hosted by the Technology Cooperation Agency (SERCOTEC) and the Economy Development Agency (CDRFO) of Chile is intended to enable Chilean government to set up appropriate policies to effectively foster design industries for the enhancement of small and medium businesses’ competitiveness.
Prof. Chung has served as the president of Korea Institute of Design Promotion (KIDP) from Feb 2000 thru May 2003.
2007.07.24 View 12670 -
KAIST Students Wins Gold Prize at Technical Idea Contest
KAIST Students Wins Gold Prize at Technical Idea Contest
- Receive the gold prize at the 3rd High-Tech Daejeon Technical Idea Contest for Company Establishment- For the development of a new system to convert complex web page addresses to short and meaningful addresses
Sang-Hoon Kim, Song-Hwa Chae and Dong-Hun Lee of Chemical and Biomolecular Engineering won the gold prize at the prospective company establishment part in the 3rd High-Tech Daejeon Technical Idea Contest for Company Establishment on May 21 for their valuable development of ‘Web Page Address Clipping System’.
So far, simplified web page addresses include special characters, which make the addresses long and complex. That is, the current address simplification service combines meaningless random words and numerals to create addresses when web page addresses are entered. In this case, the addresses are not easy to share with others and reuse several times since they are difficult to memorize.
However, the ‘Web Page Address Clipping System’ shortens meaningless long addresses. In addition, the improved address simplification service will provide user’s own addresses, and statistics and ranking to clipping addresses frequently used.
Based on this technology, Kim and Chae are now preparing to open a company called ‘URLClip’ under the auspice of Professor Tae-Yong Yang and Researcher In-Soo Kim, KAIST Entrepreneurship Center. They are also expanding their service areas onto clipping library for individual users, host name services for enterprises, etc. and developing tool bar, RSS service (RSS is an acronym of RDF (or Rich) Site Summary. It refers to a service that automatically and easily provides frequently updated contents such as news and blogs to users), etc. to improve users’ conveniences.
URLClip (http://www.urlclip.net) is a next generation portal site, which is expected to provide a variety of individualized services based on Web Page Address Clipping Service and to be used by many enterprises as well as individual users who wish to enhance their access to useful contents.
“Chemical & Biomolecular Engineering Professor Sun-Won Park has offered lots of helps and supports, so I could decide to commercialize the developed technologies. The application of this technology to real life will allow further comfortable uses of internet to users,” Kim said.
Narae Team received the best prize last April at the 2nd Pre-Star Venture Company-Opening Contest hosted by KAIST and Hanbat Univeristy, and the technology is pending a patent application.
Inquiry:Sang-Hoon Kim, Dep. of Chemical and Biomolecular Engineering, H.P. 010-4754-9947Song-Hwa Chae, Dep. of Chemical and Biomolecular Engineering, H.P. 010-7223-9947Home page: http://www.urlclip.netEmail: urlclip@urlclip.net
2007.06.05 View 14661