PAL
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KAIST and Hyundai Motors Collaborate to Develop Ultra-Fast Hydrogen Leak Detection within 0.6 Seconds
Recently, as the spread of eco-friendly hydrogen cars increases, the importance of hydrogen sensors is also on the rise. In particular, achieving technology to detect hydrogen leaks within one second remains a challenging task. Accordingly, the development of the world's first hydrogen sensor that meets the performance standards of the U.S. Department of Energy has become a hot topic.
A team at KAIST led by Dr. Min-Seung Jo from Professor Jun-Bo Yoon's team in the Department of Electrical and Electronic Engineering has successfully achieved all of its desired performance indicators, meeting globally recognized standards through collaboration with the Electromagnetic Energy Materials Research Team at Hyundai Motor Company's Basic Materials Research Center and Professor Min-Ho Seo of Pusan National University. On January 10th, the research group announced that the world's first hydrogen sensor with a speed of less than 0.6 seconds had been developed.
In order to secure faster and more stable hydrogen detection technology than existing commercialized hydrogen sensors, the KAIST team began developing a next-generation hydrogen sensor in 2021 together with Hyundai Motor Company, and succeeded after two years of development.
< Figure 1. (Left) The conceptual drawing of the structure of the coplanar heater-integrated hydrogen sensor. Pd nanowire is stably suspended in the air even with its thickness of 20 nm. (Right) A graph of hydrogen sensor performance operating within 0.6 seconds for hydrogen at a concentration of 0.1 to 4% >
Existing hydrogen sensor research has mainly focused on sensing materials, such as catalytic treatments or the alloying of palladium (Pd) materials, which are widely used in hydrogen sensors. Although these studies showed excellent performance with certain performance indicators, they did not meet all of the desired performance indicators and commercialization was limited due to the difficulty of batch processing.
To overcome this, the research team developed a sensor that satisfied all of the performance indicators by combining independent micro/nano structure design and process technology based on pure palladium materials. In addition, considering future mass production, pure metal materials with fewer material restrictions were used rather than synthetic materials, and a next-generation hydrogen sensor was developed that can be mass-produced based on a semiconductor batch process.
The developed device is a differential coplanar device in which the heater and sensing materials are integrated side by side on the same plane to overcome the uneven temperature distribution of existing gas sensors, which have a structure where the heater, insulating layer, and sensing materials are stacked vertically. The palladium nanomaterial, which is a sensing material, has a completely floating structure and is exposed to air from beneath, maximizing the reaction area with a gas to ensure a fast reaction speed. In addition, the palladium sensing material operates at a uniform temperature throughout the entire area, and the research team was able to secure a fast operation speed, wide sensing concentration, and temperature/humidity insensitivity by accurately controlling temperature-sensitive sensing performance.
< Figure 2. Electron microscopy of the coplanar heater-integrated hydrogen sensor (left) Photo of the entire device (top right) Pd nanowire suspended in the air (bottom right) Cross section of Pd nanowire >
The research team packaged the fabricated device with a Bluetooth module to create an integrated module that wirelessly detects hydrogen leaks within one second and then verified its performance. Unlike existing high-performance optical hydrogen sensors, this one is highly portable and can be used in a variety of applications where hydrogen energy is used.
Dr. Min-Seung Jo, who led the research, said, “The results of this research are of significant value as they not only operate at high speeds by exceeding the performance limits of existing hydrogen sensors, but also secure the reliability and stability necessary for actual use, and can be used in various places such as automobiles, hydrogen charging stations, and homes.” He also revealed his future plans, saying, “Through the commercialization of this hydrogen sensor technology, I would like to contribute to advancing the safe and eco-friendly use of hydrogen energy.”
< Figure 3. (Left) Real-time hydrogen detection results from the coplanar heater-integrated hydrogen sensor integrated and packaged in wireless communication and an app for mobile phone. (Middle) LED blinking cycle control in accordance with the hydrogen concentration level. (Right) Results of performance confirmation of the detection within 1 second in a real-time hydrogen leak demo >
The research team is currently working with Hyundai Motor Company to manufacture the device on a wafer scale and then mount it on a vehicle module to further verify detection and durability performance.
This research, conducted by Dr. Min-Seung Jo as the first author, has three patent applications filed in the U.S. and Korea, and was published in the renowned international academic journal 'ACS Nano'. (Paper title: Ultrafast (∼0.6 s), Robust, and Highly Linear Hydrogen Detection up to 10% Using Fully Suspended Pure Pd Nanowire). (Impact Factor: 18.087). ( https://pubs.acs.org/doi/10.1021/acsnano.3c06806?fig=fig1&ref=pdf )
The research was conducted through support from the National Research Foundation of Korea's Nano and Materials Technology Development Project and support and joint development efforts from Hyundai Motor Company's Basic Materials Research Center.
2024.01.25 View 3097 -
Every Moment of Ultrafast Chemical Bonding Now Captured on Film
- The emerging moment of bond formation, two separate bonding steps, and subsequent vibrational motions were visualized. -
< Emergence of molecular vibrations and the evolution to covalent bonds observed in the research. Video Credit: KEK IMSS >
A team of South Korean researchers led by Professor Hyotcherl Ihee from the Department of Chemistry at KAIST reported the direct observation of the birthing moment of chemical bonds by tracking real-time atomic positions in the molecule. Professor Ihee, who also serves as Associate Director of the Center for Nanomaterials and Chemical Reactions at the Institute for Basic Science (IBS), conducted this study in collaboration with scientists at the Institute of Materials Structure Science of High Energy Accelerator Research Organization (KEK IMSS, Japan), RIKEN (Japan), and Pohang Accelerator Laboratory (PAL, South Korea). This work was published in Nature on June 24.
Targeted cancer drugs work by striking a tight bond between cancer cell and specific molecular targets that are involved in the growth and spread of cancer. Detailed images of such chemical bonding sites or pathways can provide key information necessary for maximizing the efficacy of oncogene treatments. However, atomic movements in a molecule have never been captured in the middle of the action, not even for an extremely simple molecule such as a triatomic molecule, made of only three atoms.
Professor Ihee's group and their international collaborators finally succeeded in capturing the ongoing reaction process of the chemical bond formation in the gold trimer. "The femtosecond-resolution images revealed that such molecular events took place in two separate stages, not simultaneously as previously assumed," says Professor Ihee, the corresponding author of the study. "The atoms in the gold trimer complex atoms remain in motion even after the chemical bonding is complete. The distance between the atoms increased and decreased periodically, exhibiting the molecular vibration. These visualized molecular vibrations allowed us to name the characteristic motion of each observed vibrational mode." adds Professor Ihee.
Atoms move extremely fast at a scale of femtosecond (fs) ― quadrillionths (or millionths of a billionth) of a second. Its movement is minute in the level of angstrom equal to one ten-billionth of a meter. They are especially elusive during the transition state where reaction intermediates are transitioning from reactants to products in a flash. The KAIST-IBS research team made this experimentally challenging task possible by using femtosecond x-ray liquidography (solution scattering). This experimental technique combines laser photolysis and x-ray scattering techniques. When a laser pulse strikes the sample, X-rays scatter and initiate the chemical bond formation reaction in the gold trimer complex. Femtosecond x-ray pulses obtained from a special light source called an x-ray free-electron laser (XFEL) were used to interrogate the bond-forming process. The experiments were performed at two XFEL facilities (4th generation linear accelerator) that are PAL-XFEL in South Korea and SACLA in Japan, and this study was conducted in collaboration with researchers from KEK IMSS, PAL, RIKEN, and the Japan Synchrotron Radiation Research Institute (JASRI).
Scattered waves from each atom interfere with each other and thus their x-ray scattering images are characterized by specific travel directions. The KAIST-IBS research team traced real-time positions of the three gold atoms over time by analyzing x-ray scattering images, which are determined by a three-dimensional structure of a molecule. Structural changes in the molecule complex resulted in multiple characteristic scattering images over time. When a molecule is excited by a laser pulse, multiple vibrational quantum states are simultaneously excited. The superposition of several excited vibrational quantum states is called a wave packet. The researchers tracked the wave packet in three-dimensional nuclear coordinates and found that the first half round of chemical bonding was formed within 35 fs after photoexcitation. The second half of the reaction followed within 360 fs to complete the entire reaction dynamics.
They also accurately illustrated molecular vibration motions in both temporal- and spatial-wise. This is quite a remarkable feat considering that such an ultrafast speed and a minute length of motion are quite challenging conditions for acquiring precise experimental data.
In this study, the KAIST-IBS research team improved upon their 2015 study published by Nature. In the previous study in 2015, the speed of the x-ray camera (time resolution) was limited to 500 fs, and the molecular structure had already changed to be linear with two chemical bonds within 500 fs. In this study, the progress of the bond formation and bent-to-linear structural transformation could be observed in real time, thanks to the improvement time resolution down to 100 fs. Thereby, the asynchronous bond formation mechanism in which two chemical bonds are formed in 35 fs and 360 fs, respectively, and the bent-to-linear transformation completed in 335 fs were visualized. In short, in addition to observing the beginning and end of chemical reactions, they reported every moment of the intermediate, ongoing rearrangement of nuclear configurations with dramatically improved experimental and analytical methods.
They will push this method of 'real-time tracking of atomic positions in a molecule and molecular vibration using femtosecond x-ray scattering' to reveal the mechanisms of organic and inorganic catalytic reactions and reactions involving proteins in the human body. "By directly tracking the molecular vibrations and real-time positions of all atoms in a molecule in the middle of reaction, we will be able to uncover mechanisms of various unknown organic and inorganic catalytic reactions and biochemical reactions," notes Dr. Jong Goo Kim, the lead author of the study.
Publications:
Kim, J. G., et al. (2020) ‘Mapping the emergence of molecular vibrations mediating bond formation’. Nature. Volume 582. Page 520-524. Available online at https://doi.org/10.1038/s41586-020-2417-3
Profile: Hyotcherl Ihee, Ph.D.
Professor
hyotcherl.ihee@kaist.ac.kr
http://time.kaist.ac.kr/
Ihee Laboratory
Department of Chemistry
KAIST
https://www.kaist.ac.kr
Daejeon 34141, Korea
(END)
2020.06.24 View 14769 -
Park Chosen for Principality of Monaco/ITER Postdoctoral Fellowship
(Jaesun Park in the Integrated Master's and Doctoral Degree Program )
Jaesun Park from the Department of Physics, was selected as a Principality of Monaco/ITER Postdoctoral Fellowship recipient.
This program was established by the Principality of Monaco and an international organization, ITER, in January 2008 to support postdoctoral researchers who will be working for ITER. It is a relatively competitive program because it chooses only five people every two years.
The selected postdoctoral researchers will be working for ITER for two years while conducting research projects with outstanding researchers in the field of nuclear fusion.
ITER, one of the most ambitious energy projects, was launched in 1985 with the purpose of carrying out joint research on nuclear fusion energy. Currently, about 800 people are working for this organization.
Seven ITER member countries (i.e. Korea, the European Union, the United States, China, Japan, Russia, and India) are sharing the expenses and engaging in mega-scale science projects. Korea shares 9.1% (20 billion Euro) of the total construction costs of ITER experimental devices.
Park will begin his duties in early 2019.
2018.05.04 View 7640 -
EWB-KAIST Wraps up Five-Year Project in Nepal
‘Engineers Without Borders-KAIST (EWB-KAIST)’ led by Professor Tae-ho Song from the Department of Mechanical Engineering returned to Korea on January 10 after a two-week project in Nangi, Nepal.
EWB-KAIST was established in 2012 by KAIST students and professors. Since then, the team visited Nangi, in the Annapurna region of Nepal, to engage in Appropriate Technology (AT) development projects. The projects included building passive houses and small hydroelectric power, and teaching science education. In particular, passive houses that use straw as an insulator received great a reception from the locals.
This was their last visit to Nepal, since the five-year project has now come to an end. Future projects in Mongolia will be led by Professor Buhm Soon Park from the Graduate School of Science and Technology Policy.
Professor Song commented, “I am glad that the Nepal project was successfully conducted over the last five years. To make sure the support does not end here, I will personally continue to visit the Himalayas to assist the villagers.”
EWB-KAIST is a non-profit organization that conducts activities with the aim of AT development and providing support for less-developed countries in need of the benefits of technology.
( Passive house made of straws by EWB-KAIST team in Nangi, Nepal.)
2017.02.01 View 6249 -
Korea's First MOU between a University Education Volunteer Work Group and Local Government
- 200 Adolescents from Yuseong-gu to Receive Education Community Services
Midam Scholarship committee which is composed of KAIST"s students and graduates, will draw up a contract that states that it will work together with the Yuseong-gu municipality for the development of the district education services on the 14th at the Yuseong-gu office.
Both sides will together ▲mentor the local students, ▲cooperate to run and develop creative programs, ▲exchange work for the development of the KAIST Midam Scholarship Committee, ▲conduct various other projects.
From now, the Midam Scholarship Committee will teach about 200 students in Yuseong-gu. The drawing of this contract has much meaning in that it is the first of its kind.
The Midam Scholarship Committee was founded on 2009 by students in KAIST to teach math, english, and science to students from families with low income levels.
This committee has made educational pacts with middle and high schools located in Daejeong such as Chungnam High School and Beobdong High School, and has not only taught these students but also has given scholarships to the selected students.
On one hand, the Midam Scholarship Committee has also supported 10 students in KAIST who were in need with 300000won each on the 6th. This fund was raised through the donations of alumni and mentoring projects.
The Midam Scholarship Committee has been recognized for its positive impacts on the society and has received an award from the Yuseong-gu municipality office.
2012.05.10 View 8401 -
KAIST Midam Institute Gives Donations Raised by Students
Midam Association which is consisted of students from KAIST (representatives Neung-in Jang and Minkyu Jin) has donated 300thousand won per person to ten KAIST students who are in need totaling a 3million won of donation. This donation was created through the mentoring activities of the members and donations from alumni and alumni corporations.
Midam Association which was created on July of 2009 teaches math, science, and English to children from lesser off families. It started as a club created by undergraduate students and has now turned into an NGO where other local volunteers could participate.
Currently as of March, there are ten schools including Bubdong Middle School, Jeon-min Middle School, Chungnam High School, and Jeonmin High School that have a pact with the Midam Association. The association has been conducting education assistance as well as giving donations to students in need.
Last January, UNIST has benchmarked KAIST"s Midam Association and has started free education volunteer programs in association with Ulsan city.
On the other hand, Midam Association of KAIST has been awarded a Certificate of Recognition by the Municipality of Yuseong-gu, Daejeon in recognition of their deed.
2012.05.10 View 7925
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New concept 'mole game' robot developed
A new game robot concept developed by KAIST researchers came in first place at a world-renowned virtual reality exhibition, despite being the first ever entry by a Korean team.
Professor Lee Woohun’s team from the Department of Industrial Design at KAIST won the first-place award of ‘Gran Prix du Jury’ at the famous virtual reality exhibition, Laval Virtual 2012, which was held between March 28th and April 1st, with the mole game robot, ‘MoleBot’.
MoleBot can be enjoyed in a completely physical environment unlike other virtual reality games and allows interaction between the virtual world and reality. Such imaginative interaction attracted numerous spectators during the exhibition.
The MoleBot table consists of approximately 15,000 small cubes, and as the object inside the table moves, the cubes slide as if a mole is inside. By using a joystick, users can enjoy physical interaction with the table and a wide range of games.
The MoleBot can also be operated with hand gestures using ‘Kinect’, a motion sensing input device developed by Microsoft, making it possible to enjoy games as if playing with a pet.
Professor Lee’s team came up with the project from a simple idea: ‘What if moles lived inside the table?’
The team first created a table that would hold and allow the movement of the cubes, and then placed a plastic mold underneath it with a layer of spandex in between to lessen the friction, allowing smooth and lifelike movement.
The mold contains magnets that allow the accurate delivery of mechanical movement. After two years of continued additional research, MoleBot was released to the world.
In the acceptance speech, Professor Lee said, ‘It is rare for a design team to win first place in an engineering exhibition’ and that ‘to achieve such a feat, the MoleBot’s technological creativity and artistic completeness became one’.
Professor Lee also said that ‘this concept of creating an interactive world on a table could potentially become a new game interface’ and that he would research on applying this MoleBot technology to different fields such as human-computer interaction, architecture, interior, and clothing.
Laval Virtual is a world-renowned exhibition that displays cutting edge technologies in the field of virtual reality. This year was the 14th exhibit, and over 10,000 people participated in it. The exhibition gives out 12 awards, one per field, and Professor Lee’s team won the highest award.
2012.05.07 View 10713 -
A graduating student speaks about "hope" for many disabled people who dare to have a dream of becoming a scientist.
Dong-Won Kim, a graduate student of the Mechanical Engineering Department, KAIST, will leave for the US at the end of this month to further pursue his advanced degree at University of Michigan (UM) in Ann Harbor. He has completed his master’s program at KAIST this summer, specializing in rehabilitation engineering.
Mr. Kim was born with cerebral palsy, which made him difficult to talk and use his hands. Notwithstanding the obstacles, he went through the regular school system and earned a master’s degree offered by one of the toughest universities in Korea.
When asked about what was the most difficult thing to study, he said with a gentle smile that “other than taking him a longer time to solve a math problem because of his weak hand muscle, he doesn’t have any difficulties.”
“Of course, people around me helped me a lot, but I tried to maintain my confidence in me and did my best so as not to disappoint my family and friends who have supported me,” Mr. Kim added.
Professor Pyung-Hoon Chang of the Mechanical Engineering Department, who was an adviser to Mr. Kim, recalled,
“Dong-Won has been a great student; I was quite impressed with his intellectual vigor and academic passion. He got along well with his peer students and had always positive and can-do attitude. I’m really pleased to see him graduate, given the tough situation he’s been in. He sets an inspiring role model who overcame difficulties and achieved great accomplishments.”
Mr. Kim hopes that universities including KAIST improve their educational environment to adopt friendlier policies toward the people with disabilities so that more of them can be offered an opportunity to become a scientist or engineer.
He will study medical engineering at University of Michigan—through his doctoral study, he wishes to identify causes and improvements of disabilities suffered by people and become an expert in rehabilitation.
Mr. Kim also donated 1 million won to KAIST out of his appreciation for the support he had received during his stay at the school. He said, “Although this is a small amount, I’d like to “thank you” for the members of KAIST community including its faculty and staff who have encouraged me to finish the study. If possible, I’d like to make a greater contribution in the future, and to that end, I’ll study harder and try to become the person whom I have planned for.”
Upon hearing about his generosity, President Nam Pyo Suh said, “The gift is so wonderful because it was given to us from one of our students. I wish him great success in his future study and will look forward to having his valuable contributions to our school and the nation.”
2010.08.17 View 10007 -
World Research University Heads To Discuss Global Networking at KAIST Symposium
About 70 leaders of the world"s major research universities will discuss how to strengthen and operate global networks to share faculty, students, facilities and other resources for common advancement at a symposium Monday, Sept. 8, at the Westin Chosun Hotel in Seoul organized by KAIST, Korea"s foremost institute of science and technology education and research.
Participants of the 1st International Presidential Forum on Global Research Universities are from 39 universities in 20 countries. They include nine presidents of Korean universities.
The international symposium, the first such event to be held in Korea, will proceed in five panel sessions. The subjects of each session and their keynote speakers are:
-- "Roaming Professorships: To Whose Benefit?" by Dr. John Anderson, president of the Illinois Institute of Technology, USA,-- "Dual Degree Programs: Future Potential and Challenges" by Dr. Paul Greenfield, president of the University of Queensland, Australia, -- "Sharing Facilities and Expertise" by KAIST President Nam Pyo Suh,-- "An Approach to Joint Research Ventures with NASA" by Yvonne Pendleton, NASA, and-- "Globalization through Interfacing with Existing Networking" by Dr. Lars Pallesen, rector of the Technical University of Denmark.
KAIST President Suh said of the purpose of the conference: "Research universities have become global enterprises. Collaborations that were once primarily between individual researchers are now increasingly occurring at institutional and international levels. Similarly, educating students which used to be the responsibility of a single university has now become a multi-institutional undertaking, involving many universities in different countries.
"Now leading research universities in many countries depend on the continuous supply of outstanding graduate students from the "feeder" schools of developing nations. There are concerns that the current system may not be serving the interest and need of some institutions, especially those in developing nations. This should be examined and understood to devise international mechanisms that can accentuate the positive aspects of globalization.
"Through this forum, we hope to forge an international network of universities that will strengthen the effort of individual universities and create alliance for research and education that can become a new paradigm for global collaboration."
Prime Minister Han Seung-soo will give a speech at a dinner after the conclusion of the symposium. President of the Korea International Traders Association Lee Hee-beom will make a welcoming address at the start of the conference.
Co-sponsors of the international university presidents" forum include the Dong-a Ilbo, a major national daily, and the Dong-a Science magazine.
The research universities presidential forum will be followed on Sept. 9 by an international academic workshop at KAIST"s Daejeon campus on EEWS (Energy, Environment, Water and Sustainability).
Under the theme of "Challenges as Opportunities," research teams from MIT, CalTech, the Korean Ministry of Knowledge and Economy, KAIST Institute and KAIST EEWS team will present their research results at the workshop. Major Korean businesses, including SK Energy, GS Caltex and the Samsung Group will also introduce their research programs concerning EEWS, the most pressing prblems of today"s world.
A groundbreaking ceremony will be held at the KAIST campus in the afternoon of the same day for the construction of the KI Building, which will house all the eight research institutes of KAIST. The KI for Bio Century, KI for IT Convergence, KI for Design of Complex Systems, KI for Entertainment Engineering, KI for Eco-Energy, KI for Urban Space and Systems, and the KI for Optical Science and Technology were established between 2006 and 2008. More than 230 professors from 18 departments have actively engaged in research activities in their respective fields.
KAIST will start construction of the Pappalardo Medical Center in a ceremony on Wednesday with the attendance of Mr. Neil Pappalardo, chairman-CEO of Meditech Inc. of the United States who donated $2.5 million for the project. The medical facility for KAIST students, faculty and the residents of the university area will be completed in September 2009.
The President"s Advisory Council (PAC) for KAIST will hold its 3rd general meeting on Sept. 10 to discuss KAIST"s short- and long-term strategies to become the world"s top-ranked research university. The PAC was formed in 2006 with 11 foreign and 14 domestic figures from the business and academic circles.
Foreign PAC members include John Holzrichter, president of Fannie and John Hertz Foundation; Donald C. W. Kim, chairman of AMKOR A&E, Inc.; Chong-Moon Lee, chairman of AmBex Venture Group; Byung-Joon Park, founder of Bureau Veritas CPS, Inc.; Lars Pallesen, rector of the Technical University of Denmark. PAC members have advised the KAIST president on international publicity on KAIST"s academic excellence, fund-raising, and promotion of cooperative relations with overseas institutions.
2008.09.04 View 18050