NSF
-
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 751 -
Transformative Electronics Systems to Broaden Wearable Applications
Imagine a handheld electronic gadget that can soften and deform when attached to our skin. This will be the future of electronics we all dreamed of. A research team at KAIST says their new platform called 'Transformative Electronics Systems' will open a new class of electronics, allowing reconfigurable electronic interfaces to be optimized for a variety of applications.
A team working under Professor Jae-Woong Jeong from the School of Electrical Engineering at KAIST has invented a multifunctional electronic platform that can mechanically transform its shape, flexibility, and stretchability. This platform, which was reported in Science Advances, allows users to seamlessly and precisely tune its stiffness and shape.
"This new class of electronics will not only offer robust, convenient interfaces for use in both tabletop or handheld setups, but also allow seamless integration with the skin when applied onto our bodies," said Professor Jeong.
The transformative electronics consist of a special gallium metal structure, hermetically encapsulated and sealed within a soft silicone material, combined with electronics that are designed to be flexible and stretchable. The mechanical transformation of the electronic systems is specifically triggered by temperature change events controlled by the user.
"Gallium is an interesting key material. It is biocompatible, has high rigidity in solid form, and melts at a temperature comparable to the skin's temperature," said lead author Sang-Hyuk Byun, a researcher at KAIST.
Once the transformative electronic platform comes in contact with a human body, the gallium metal encapsulated inside the silicone changes to a liquid state and softens the whole electronic structure, making it stretchable, flexible, and wearable. The gallium metal then solidifies again once the structure is peeled off the skin, making the electronic circuits stiff and stable. When flexible electronic circuits were integrated onto these transformative platforms, it empowered them with the ability to become either flexible and stretchable or rigid.
"This technology could not have been achieved without interdisciplinary efforts," said co-lead author Joo Yong Sim, who is a researcher with ETRI. "We worked together with electrical, mechanical, and biomedical engineers, as well as material scientists and neuroscientists to make this breakthrough."
This universal electronics platform allowed researchers to demonstrate applications that were highly adaptable and customizable, such as a multi-purpose personal electronics with variable stiffness and stretchability, a pressure sensor with tuneable bandwidth and sensitivity, and a neural probe that softens upon implantation into brain tissue.
Applicable for both traditional and emerging electronics technologies, this breakthrough can potentially reshape the consumer electronics industry, especially in the biomedical and robotic domains. The researchers believe that with further development, this novel electronics technology can significantly impact the way we use electronics in our daily life.
< Transformative electronics in soft mode,which becomes wearable for outdoor applications.>
Video Material:
https://youtu.be/im0J18TfShk
Publication: Sang-Hyuk Byun, Joo Yong Sim, Zhanan Zhou, Juhyun Lee, Raza Qazi, Marie C. Walicki, Kyle E. Parker, Matthew P. Haney, Su Hwan Choi, Ahnsei Shon, Graydon B. Gereau, John Bilbily, Shuo Li, Yuhao Liu, Woon-Hong Yeo, Jordan G. McCall, Jianliang Xiao, and Jae-Woong Jeong. 2019. Mechanically transformative electronics, sensors, and implantable devices. Science Advances. Volume 5. No. 11. 12 pages. https://doi.org/10.1126/sciadv.aay0418
Link to download the full-text paper: https://advances.sciencemag.org/content/advances/5/11/eaay0418.full.pdf
Profile: Prof. Jae-Woong Jeong, PhD jjeong1@kaist.ac.kr
https://www.jeongresearch.org/
Professor
Bio-Integrated Electronics and Systems Laboratory
School of Electrical Engineering
Korea Advanced Institute of Science and Technology (KAIST) https://www.kaist.ac.kr
Daejeon 34141, Korea
Profile: Sang-Hyuk Byun, PhD Candidate
shbun95@kaist.ac.kr
(END)
2020.01.31 View 328 -
A Mathematical Model Reveals Long-Distance Cell Communication Mechanism
How can tens of thousands of people in a large football stadium all clap together with the same beat even though they can only hear the people near them clapping?
A combination of a partial differential equation and a synthetic circuit in microbes answers this question. An interdisciplinary collaborative team of Professor Jae Kyoung Kim at KAIST, Professor Krešimir Josić at the University of Houston, and Professor Matt Bennett at Rice University has identified how a large community can communicate with each other almost simultaneously even with very short distance signaling. The research was reported at Nature Chemical Biology.
Cells often communicate using signaling molecules, which can travel only a short distance. Nevertheless, the cells can also communicate over large distances to spur collective action. The team revealed a cell communication mechanism that quickly forms a network of local interactions to spur collective action, even in large communities.
The research team used an engineered transcriptional circuit of combined positive and negative feedback loops in E. coli, which can periodically release two types of signaling molecules: activator and repressor. As the signaling molecules travel over a short distance, cells can only talk to their nearest neighbors. However, cell communities synchronize oscillatory gene expression in spatially extended systems as long as the transcriptional circuit contains a positive feedback loop for the activator.
Professor Kim said that analyzing and understanding such high-dimensional dynamics was extremely difficult. He explained, “That’s why we used high-dimensional partial differential equation to describe the system based on the interactions among various types of molecules.” Surprisingly, the mathematical model accurately simulates the synthesis of the signaling molecules in the cell and their spatial diffusion throughout the chamber and their effect on neighboring cells.
The team simplified the high-dimensional system into a one-dimensional orbit, noting that the system repeats periodically. This allowed them to discover that cells can make one voice when they lowered their own voice and listened to the others. “It turns out the positive feedback loop reduces the distance between moving points and finally makes them move all together. That’s why you clap louder when you hear applause from nearby neighbors and everyone eventually claps together at almost the same time,” said Professor Kim.
Professor Kim added, “Math is a powerful as it simplifies complex thing so that we can find an essential underlying property. This finding would not have been possible without the simplification of complex systems using mathematics."
The National Institutes of Health, the National Science Foundation, the Robert A. Welch Foundation, the Hamill Foundation, the National Research Foundation of Korea, and the T.J. Park Science Fellowship of POSCO supported the research.
(Figure: Complex molecular interactions among microbial consortia is simplified as interactions among points on a limit cycle (right).)
2019.10.15 View 11919 -
OUIC Presents the Six Most Promising Techs Transferrable to Local SMEs
KAIST will showcase the six most promising technologies for small and medium enterprises (SMEs) on November 14 in the Academic Cultural Complex. To strengthen the competitive edge of local SMEs in Daejeon, the Office of University-Industry made a survey of their technological needs and came up with the six most promising technologies. Developers will introduce their technologies during the session.Besides the introduction of the promising technologies, the session will also provide a program named University to Business (U2B) to match up technologies according to the SMEs’ needs. SMEs who wish to engage in technology transfers can receive counseling and other support programs during the session.First, Professor Seok-Hyung Bae from the Department of Industrial Design will present a technology for controlling cooperation robots. Professor Bae inserted flexible materials between the controllers to allow robots to use both hands stably and operate more accurately and swiftly. It can be applied to automatic robots, industrial robots, and service robots.Professor Hyun Myung from the Department of Civil & Environmental Engineering will demonstrate a robot navigation system in a dynamic indoor and outdoor environment, which can be applied to robotics in logistics, smart factories, and autonomous vehicles. Providing robust simultaneous localization and mapping systems, this technology shows high-performing navigation with low-cost sensors.Meanwhile, Professor Siyoung Choi from the Department of Chemical and Biomolecular Engineering will introduce a technology for forming stable adhesive emulsions. An emulsion is a stable mixture of water and oil. Conventionally, a small amount of surfactant is added to stabilize an emulsion. Here, Professor Choi developed a stable emulsion system without using any chemical substances. This technology can be applied to various fields, including the cosmetics, pharmaceutical, semiconductor, and painting industries. The session will also present smart IoTs platform technology developed by Professor Jinhong Yang from the KAIST Institute for IT Convergence. His technology minimizes errors occurring when multiple IoT devices are connected simultaneously. Professor Yong Keun Park from the Department of Physics will introduce a technology for measuring glycated hemoglobin by using the optical properties of red blood cells. This technology can be applied to make low-cost, small-sized measuring equipment. It can also be used for vitro diagnoses including diabetes, cardiovascular disorders, tumors, kidney disease, and infectious diseases. Professor Yong Man Ro from the School of Electrical Engineering will show technology for biometric access control. Conventional technologies for face recognition fall behind other biometrics. Professor Ro and his team developed a facial dynamics interpreting network which allows very accurate facial recognition by interpreting the relationships between facial local dynamics and estimating facial traits. This technology can be applied to security and communication in finance, computers, and information system.KAIST President Sung-Chul Shin said, “KAIST will continue to support SMEs to have stronger competitiveness in the market. Through technology transfer, we will drive innovation in technological commercialization where a university’s research and development creates economic value.”
2018.11.13 View 917 -
In Jin Cho Earned the Best Poster Prize at ME Summit 2017
In Jin Cho, a Ph.D. student in the Department of Chemical and Biomolecular Engineering at KAIST received the best poster prize at the International Metabolic Engineering Summit 2017 held on October 24 in Beijing, China.
The International Metabolic Engineering Summit is a global conference where scientists and corporate researchers in the field of metabolic engineering present their latest research outcomes and build networks.
At this year’s summit, about 500 researchers from around the world participated in active academic exchanges, including giving keynote speeches and presenting posters.
During the poster session, the summit selects one person for the KeAi-synthetic and Systems Biotechnology Poster Award, two for Microbial Cell Factories Poster Awards, and three for Biotechnology Journal Poster Awards among the posters presented by graduate students, post-doctoral fellows and researchers. Cho received the KeAi-synthetic and Systems Biotechnology Poster Award. Her winning poster is on the biotransformation of p-xylene to terephthalic acid using engineered Escherichia coli.
Terephthalic acid is generally produced by p-xylene oxidation; however, this process requires a high temperature and pressure as well as a toxic catalyst during the reaction process.
Cho and Ziwei Luo, a Ph.D. student at KAIST, co-conducted the research and developed a successful biological conversion process. Compared to the existing chemical process, it does not require a high temperature and pressure; and it is environmentally friendly with a relatively high conversion rate of approximately 97%.
Cho’s advisor, Distinguished Professor Sang Yup Lee said, “Further research on glucose-derived terephthalic acid will enable us to produce biomass-based eco-friendly terephthalic acid through engineered Escherichia coli.”
2017.10.31 View 1955 -
Dr. Ryu of KAIST Receives the S-Oil Outstanding Paper Award
Dr. Je-Kyung Ryu of KAIST’s Department of Physics has been awarded the S-Oil Outstanding Paper Award for his doctoral dissertation’s originality and applicability.
Professor Tae-Young Yoon of Physics is his doctoral advisor.
The award ceremony took place on November 25, 2015 at the Press Center in Seoul.
This S-Oil Outstanding Paper Award, jointly sponsored by the Korean Academy of Science and Technology (KAST) and the Scholastic University Presidential Association, was established to foster young talented scientists in basic science and to advance the field.
The award is given every other year for each of the fields of physics, chemistry, mathematics, biology, and earth sciences.
With the award, Dr. Ryu received a research grant of USD 8,600.
He discovered, for the first time in the world, how NSF (N-ethylmaleimide-sensitive factor), a protein involved in a vesicular transport in cellular activities, disassembles a SNARE (soluble NSF attachment protein receptor) complex, using a unimolecular biophysics method.
Unlike the existing studies, he proposed a model in which NSF disassembles SNARE complexes at one step, and as a result, provided evidence of how the SNARE complex influenced the fusion of biological membranes.
His research was published in the scientific journal Science issued on March 27, 2015. The title of the paper is “Spring-loaded Unraveling of a Single SNARE Complex by NSF in One Round of ATP Turnover.”
2015.11.27 View 2686 -
Professor Ki-Jun Jeong Wins the 2015 Dam Yeun Academic Award
The 11th Dam Yeun Academic Award presented by the Korean Society for Biotechnology and Bioengineering (KSBB) to a biologist under 45 years old went to Professor Ki-Jun Jeong of the Chemical and Biomolecular Engineering Department at KAIST.
The award ceremony took place on October 13, 2015, at the annual conference of KSBB held at Songdo Convensia in Incheon City.
Each year KSBB announces the recipient of the award based on the publications by researchers in the last five years at peer-reviewed international journals or KSBB Journal as well as the record of patent registration and technology transfers.
Professor Jeong is recognized for his pioneering research in protein, antibody, cellular engineering, and protein displays and chips.
2015.10.19 View 3022 -
KAIST's Research Team Receives the Best Paper Award from the IEEE Transaction on Power Electronics
A research team led by Professor Chun T. Rim of the Department of Nuclear and Quantum Engineering at the Korea Advanced Institute of Science and Technology (KAIST) has received the First Prize Papers Award from the IEEE (Institute of Electrical and Electronics Engineers) Transactions on Power Electronics (TPEL), a peer-reviewed journal that covers fundamental technologies used in the control and conversion of electric power.
A total of three research papers received this award in 2015.
Each year, TPEL’s editors select three best papers among those published in the journal during the preceding calendar year. In 2014, the TPEL published 579 papers. Professor Rim’s paper was picked out as one of the three papers published last year for the First Prize Papers Award.
Entitled “Generalized Active EMF (electromagnetic field) Cancel Methods for Wireless Electric Vehicles (http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=6684288&tag=1),” the paper proposed, for the first time in the world, three generalized design methods for cancelling the total EMF generated from wireless electric vehicles. This technology, researchers said, can be applied to any wireless power transfer systems.
The award ceremony will be held at the upcoming conference of the 2015 IEEE Energy Conversion Congress and Expo in September in Montreal, Canada.
2015.08.27 View 2820 -
KAIST and Petersburg State Transport University Sign a MOU on Green Transportation
The Petersburg State Transport University (PSTU) in Russia is a higher education institution specializing in railway transport.
KAIST and PSTU signed a memorandum of understating (MOU) on October 28, 2014 at the KAIST campus and agreed to collaborate in the research of and hold academic exchanges for green transportation.
Based on the agreement, the two institutions will collaborate in the development of a high capacity railway that is powered through wireless power transfer technology and will exchange personnel and academic knowledge to advance the field of green transportation.
The Graduate School for Green Transportation (GSGT) at KAIST organized a seminar which took place after the MOU signing ceremony. Professor Dong-Ho Cho, the Dean of GSGT, presented a keynote speech at the seminar on “Korea’s Green Transportation Policy and Its Technology Development Status” to the audience including the PSTU delegation.
Established in 1809, PSTU is one of the oldest and most prestigious engineering universities in Russia, serving as an important scientific and research center in the area of engineering, construction, and railway operation.
2014.11.04 View 5120 -
President Steve Kang of KAIST Attends the 2014 Summer Davos Forum in Tianjin, China
President Steve Kang of KAIST will attend the 2014 Annual Meeting of the New Champions, the World Economic Forum (WEF), to be held on September 10-12, 2014 in Tianjin, China.
KAIST holds its own IdeasLab session on nanotechnology on September 12, 2014.
On September 10, 2014, President Steve Kang will participate in a private session hosted by the Global University Leaders Forum (GULF) community at WEF as a panelist.
In addition to President Kang, eight presidents from top global universities such as the National University of Singapore, Peking University, ETH Zurich (Swiss Federal Institute of Technology), University of Tokyo, and Carnegie Mellon University will join the panel discussion under the topic, “Increasing the Translational Impact of University Research.” Specifically, the presidents will address issues related to the importance of university-led technology transfer in Asia, key strategies and goals for technology transfer, and implementation approaches taken by each university to promote technology transfer from university to industry.
President Kang was invited to this GULF session, the only attendant from Korean universities, in recognition of his long time experience and expertise in education and research.
In 2006, WEF created the GULF, a small community of the presidents of top universities in the world, aiming to offer an open platform for high-level dialogues on issues of higher education and research with other sectors, as well as to foster collaboration between universities in areas of significance for global policy.
As of 2014, a total of 25 globally leading universities, including Harvard University, University of Cambridge, and Massachusetts Institute of Technology, are GULF members. KAIST, which joined the club this year, is the only Korean university.
The 2014 Annual Meeting of the New Champions, also known as the Summer Davos Forum, hosts numerous sessions under the theme of “Creating Value through Innovation.” At the Forum, a total of ten IdeasLab sessions will be hosted. KAIST was invited to run its own IdeasLab on nanotechnology on September 12, 2014.
Together with President Kang, Professors Sang Ouk Kim and Keon Jae Lee from the Department of Materials Science Engineering, KAIST, and Professors Sang Yup Lee and Hyunjoo Lee from the Department of Chemical and Biomolecular Engineering, KAIST, will present their own speeches on the topic entitled “From diagnostics to materials, how is nanotechnology changing lives?”
President Kang will give the opening speech at the KAIST IdeasLab.
He said that an invitation from WEF to join the IdeasLab spoke well for KAIST:
“KAIST is the first and the only Korean university ever invited to run its own IdeasLab at the World Economic Forum. The IdeasLab is an expert group meeting, conducted only by the world’s most prestigious universities and research institutes. At the IdeasLab sessions, global leaders from different sectors identify major issues facing higher education and humanity and explore solutions through science and technology innovation. Holding our own IdeasLab on one of our strongest fields, nanotechnology, is indeed an excellent opportunity for KAIST to show its strength in academic and research excellence on the global stage.”
2014.09.08 View 5630 -
Book Announcement: The Transformative Power of Service Innovation
Professor
Tae-Sung Yoon of the Technology Management Graduate School at KAIST has
recently published a book entitled
The
Transformative Power of Service Innovation
(available only in Korean).
In the
book, Professor Yoon presents many examples of successful service innovations
and explores the topic of how excellence in innovation can be achieved through the
convergence of diverse fields and industries.
2014.04.01 View 5017 -
Professor Sang-Min received an award for scholar of the year from the KAISTian of the Year 2013
KAIST nominates a “Scholar of the Year” each year and presents the award to the recipient at a New Year’s opening ceremony. For the year 2013, Professor Sang-Min Bae of the Industrial Design Department at KAIST was named “KAIST Scholar of 2013” and received the award on January 2, 2014.
Professor Bae has been recognized for his design achievement in 2013: D’Light, a kinetic lighting that employs a transformable lampshade using flexible honeycomb structure, became one of the finalists in the living room and bedroom category of the International Design Excellence Award 2013 and was selected one of the best 100 for the 2013 Good Design Award. Users can easily change the shape and light intensity of the lamp by simply pivoting the lampshade with its small handle.
Professor Bae has also actively pursued his own philanthrophic projects through design: he has given the profits from the sales of his designs including D’Light directly toward a scholarship for needy children.
The Scholar of the Year award is presented to a faculty member or researcher at KAIST who has contributed to the advancement of science and technology such as publication of articles with influential research outcomes, invention of breakthrough technology, implementation of outstanding research projects, and improvement of public life. Professor Bae is the 13 th winner of the KAIST award.
The Korea Times, a leading English language newspaper in Korea, published an article on this award. For the article, please visit http://www.koreatimes.co.kr/www/news/people/2014/01/178_149117.html .
2014.01.09 View 6547