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From Dark to Light in a Flash: Smart Film Lets Windows Switch Autonomously
Researchers have developed a new easy-to-use smart optical film technology that allows smart window devices to autonomously switch between transparent and opaque states in response to the surrounding light conditions.
The proposed 3D hybrid nanocomposite film with a highly periodic network structure has empirically demonstrated its high speed and performance, enabling the smart window to quantify and self-regulate its high-contrast optical transmittance. As a proof of concept, a mobile-app-enabled smart window device for Internet of Things (IoT) applications has been realized using the proposed smart optical film with successful expansion to the 3-by-3-inch scale. This energy-efficient and cost-effective technology holds great promise for future use in various applications that require active optical transmission modulation.
Flexible optical transmission modulation technologies for smart applications including privacy-protection windows, zero-energy buildings, and beam projection screens have been in the spotlight in recent years. Conventional technologies that used external stimuli such as electricity, heat, or light to modulate optical transmission had only limited applications due to their slow response speeds, unnecessary color switching, and low durability, stability, and safety.
The optical transmission modulation contrast achieved by controlling the light scattering interfaces on non-periodic 2D surface structures that often have low optical density such as cracks, wrinkles, and pillars is also generally low. In addition, since the light scattering interfaces are exposed and not subject to any passivation, they can be vulnerable to external damage and may lose optical transmission modulation functions. Furthermore, in-plane scattering interfaces that randomly exist on the surface make large-area modulation with uniformity difficult.
Inspired by these limitations, a KAIST research team led by Professor Seokwoo Jeon from the Department of Materials Science and Engineering and Professor Jung-Wuk Hong of the Civil and Environmental Engineering Department used proximity-field nanopatterning (PnP) technology that effectively produces highly periodic 3D hybrid nanostructures, and an atomic layer deposition (ALD) technique that allows the precise control of oxide deposition and the high-quality fabrication of semiconductor devices.
The team then successfully produced a large-scale smart optical film with a size of 3 by 3 inches in which ultrathin alumina nanoshells are inserted between the elastomers in a periodic 3D nanonetwork.
This “mechano-responsive” 3D hybrid nanocomposite film with a highly periodic network structure is the largest smart optical transmission modulation film that exists. The film has been shown to have state-of-the-art optical transmission modulation of up to 74% at visible wavelengths from 90% initial transmission to 16% in the scattering state under strain. Its durability and stability were proved by more than 10,000 tests of harsh mechanical deformation including stretching, releasing, bending, and being placed under high temperatures of up to 70°C. When this film was used, the transmittance of the smart window device was adjusted promptly and automatically within one second in response to the surrounding light conditions. Through these experiments, the underlying physics of optical scattering phenomena occurring in the heterogeneous interfaces were identified. Their findings were reported in the online edition of Advanced Science on April 26. KAIST Professor Jong-Hwa Shin’s group and Professor Young-Seok Shim at Silla University also collaborated on this project.
Donghwi Cho, a PhD candidate in materials science and engineering at KAIST and co-lead author of the study, said, “Our smart optical film technology can better control high-contrast optical transmittance by relatively simple operating principles and with low energy consumption and costs.”
“When this technology is applied by simply attaching the film to a conventional smart window glass surface without replacing the existing window system, fast switching and uniform tinting are possible while also securing durability, stability, and safety. In addition, its wide range of applications for stretchable or rollable devices such as wall-type displays for a beam projection screen will also fulfill aesthetic needs,” he added.
This work was supported by the National Research Foundation of Korea (NRF), and the Korean Ministries of Science, ICT and Future Planning (MSIP), and Science and ICT (MSIT).
Publication:
Cho, D, et al. (2020) ‘High-Contrast Optical Modulation from Strain-Indicated Nanogaps at 3D Heterogeneous Interfaces’ Advanced Science, 1903708. Available online at https://doi.org/10.1002/advs.201903708
Profile: Seokwoo Jeon, PhD
Professor
jeon39@kaist.ac.kr
https://fdml.kaist.ac.kr/
Flexible Device and Metamaterials Lab (FDML)
Department of Materials Science and Engineering (MSE)
Korea Advanced Institute of Science and Technology (KAIST)
https://www.kaist.ac.krDaejeon 34141, Korea
Profile: Jung-Wuk Hong, PhD
Associate Professor
j.hong@kaist.ac.kr
http://aaml.kaist.ac.kr
Advanced Applied Mechanics Laboratory (AAML)
Department of Civil and Environmental Engineering
KAIST
Profile: Donghwi Cho
PhD Candidate
roy0202@kaist.ac.krFDML, MSE, KAIST
Profile: Young-Seok Shim, PhD
Assistant Professor
ysshim@silla.ac.kr
Division of Materials Science and Engineering Silla University
https://www.silla.ac.kr
Busan 46958, Korea
(END)
2020.06.02 View 13477 -
Universal Virus Detection Platform to Expedite Viral Diagnosis
Reactive polymer-based tester pre-screens dsRNAs of a wide range of viruses without their genome sequences
The prompt, precise, and massive detection of a virus is the key to combat infectious diseases such as Covid-19. A new viral diagnostic strategy using reactive polymer-grafted, double-stranded RNAs will serve as a pre-screening tester for a wide range of viruses with enhanced sensitivity.
Currently, the most widely using viral detection methodology is polymerase chain reaction (PCR) diagnosis, which amplifies and detects a piece of the viral genome. Prior knowledge of the relevant primer nucleic acids of the virus is quintessential for this test.
The detection platform developed by KAIST researchers identifies viral activities without amplifying specific nucleic acid targets. The research team, co-led by Professor Sheng Li and Professor Yoosik Kim from the Department of Chemical and Biomolecular Engineering, constructed a universal virus detection platform by utilizing the distinct features of the PPFPA-grafted surface and double-stranded RNAs.
The key principle of this platform is utilizing the distinct feature of reactive polymer-grafted surfaces, which serve as a versatile platform for the immobilization of functional molecules. These activated surfaces can be used in a wide range of applications including separation, delivery, and detection. As long double-stranded RNAs are common byproducts of viral transcription and replication, these PPFPA-grafted surfaces can detect the presence of different kinds of viruses without prior knowledge of their genomic sequences.
“We employed the PPFPA-grafted silicon surface to develop a universal virus detection platform by immobilizing antibodies that recognize double-stranded RNAs,” said Professor Kim.
To increase detection sensitivity, the research team devised two-step detection process analogues to sandwich enzyme-linked immunosorbent assay where the bound double-stranded RNAs are then visualized using fluorophore-tagged antibodies that also recognize the RNAs’ double-stranded secondary structure.
By utilizing the developed platform, long double-stranded RNAs can be detected and visualized from an RNA mixture as well as from total cell lysates, which contain a mixture of various abundant contaminants such as DNAs and proteins.
The research team successfully detected elevated levels of hepatitis C and A viruses with this tool.
“This new technology allows us to take on virus detection from a new perspective. By targeting a common biomarker, viral double-stranded RNAs, we can develop a pre-screening platform that can quickly differentiate infected populations from non-infected ones,” said Professor Li.
“This detection platform provides new perspectives for diagnosing infectious diseases. This will provide fast and accurate diagnoses for an infected population and prevent the influx of massive outbreaks,” said Professor Kim.
This work is featured in Biomacromolecules. This work was supported by the Agency for Defense Development (Grant UD170039ID), the Ministry of Science and ICT (NRF-2017R1D1A1B03034660, NRF-2019R1C1C1006672), and the KAIST Future Systems Healthcare Project from the Ministry of Science and ICT (KAISTHEALTHCARE42).
Profile:-Professor Yoosik KimDepartment of Chemical and Biomolecular Engineeringhttps://qcbio.kaist.ac.kr
KAIST-Professor Sheng LiDepartment of Chemical and Biomolecular Engineeringhttps://bcpolymer.kaist.ac.kr
KAIST
Publication:Ku et al., 2020. Reactive Polymer Targeting dsRNA as Universal Virus Detection Platform with Enhanced Sensitivity. Biomacromolecules (https://doi.org/10.1021/acs.biomac.0c00379).
2020.06.01 View 18852 -
Visualization of Functional Components to Characterize Optimal Composite Electrodes
Researchers have developed a visualization method that will determine the distribution of components in battery electrodes using atomic force microscopy. The method provides insights into the optimal conditions of composite electrodes and takes us one step closer to being able to manufacture next-generation all-solid-state batteries.
Lithium-ion batteries are widely used in smart devices and vehicles. However, their flammability makes them a safety concern, arising from potential leakage of liquid electrolytes.
All-solid-state lithium ion batteries have emerged as an alternative because of their better safety and wider electrochemical stability. Despite their advantages, all-solid-state lithium ion batteries still have drawbacks such as limited ion conductivity, insufficient contact areas, and high interfacial resistance between the electrode and solid electrolyte.
To solve these issues, studies have been conducted on composite electrodes in which lithium ion conducting additives are dispersed as a medium to provide ion conductive paths at the interface and increase the overall ionic conductivity.
It is very important to identify the shape and distribution of the components used in active materials, ion conductors, binders, and conductive additives on a microscopic scale for significantly improving the battery operation performance.
The developed method is able to distinguish regions of each component based on detected signal sensitivity, by using various modes of atomic force microscopy on a multiscale basis, including electrochemical strain microscopy and lateral force microscopy.
For this research project, both conventional electrodes and composite electrodes were tested, and the results were compared. Individual regions were distinguished and nanoscale correlation between ion reactivity distribution and friction force distribution within a single region was determined to examine the effect of the distribution of binder on the electrochemical strain.
The research team explored the electrochemical strain microscopy amplitude/phase and lateral force microscopy friction force dependence on the AC drive voltage and the tip loading force, and used their sensitivities as markers for each component in the composite anode.
This method allows for direct multiscale observation of the composite electrode in ambient condition, distinguishing various components and measuring their properties simultaneously.
Lead author Dr. Hongjun Kim said, “It is easy to prepare the test sample for observation while providing much higher spatial resolution and intensity resolution for detected signals.” He added, “The method also has the advantage of providing 3D surface morphology information for the observed specimens.”
Professor Seungbum Hong from the Department of Material Sciences and Engineering said, “This analytical technique using atomic force microscopy will be useful for quantitatively understanding what role each component of a composite material plays in the final properties.”
“Our method not only will suggest the new direction for next-generation all-solid-state battery design on a multiscale basis but also lay the groundwork for innovation in the manufacturing process of other electrochemical materials.”
This study is published in ACS Applied Energy Materials and supported by the Big Science Research and Development Project under the Ministry of Science and ICT and the National Research Foundation of Korea, the Basic Research Project under the Wearable Platform Materials Technology Center, and KAIST Global Singularity Research Program for 2019 and 2020.
Publication:Kim, H, et al. (2020) ‘Visualization of Functional Components in a Lithium Silicon Titanium Phosphate-Natural Graphite Composite Anode’. ACS Applied Energy Materials, Volume 3, Issue 4, pp. 3253-3261. Available online at https://doi.org/10.1021/acsaem.9b02045
Profile:
Seungbum Hong
Professor
seungbum@kaist.ac.kr
http://mii.kaist.ac.kr/
Materials Imaging and Integration Laboratory
Department of Material Sciences and Engineering
KAIST
2020.05.22 View 10179 -
Highly Efficient Charge-to-Spin Interconversion in Graphene Heterostructures
Researchers present a new route for designing a graphene-based active spintronic component
KAIST physicists described a route to design the energy-efficient generation, manipulation and detection of spin currents using nonmagnetic two-dimensional materials. The research team, led by Professor Sungjae Cho, observed highly efficient charge-to-spin interconversion via the gate-tunable Rashba-Edelstien effect (REE) in graphene heterostructures.
This research paves the way for the application of graphene as an active spintronic component for generating, controlling, and detecting spin current without ferromagnetic electrodes or magnetic fields.
Graphene is a promising spintronic component owing to its long spin diffusion length. However, its small spin-orbit coupling limits the potential of graphene in spintronic applications since graphene cannot be used to generate, control, or detect spin current.
“We successfully increased the spin-orbit coupling of graphene by stacking graphene on top of 2H-TaS2, which is one of the transition metal dichalcogenide materials with the largest spin-orbit coupling. Graphene now can be used to generate, control, and detect spin current,” Professor Cho said.
The Rashba-Edelstein effect is a physical mechanism that enables charge current-to-spin current interconversion by spin-dependent band structure induced by the Rashba effect, a momentum-dependent splitting of spin bands in low-dimensional condensed matter systems.
Professor Cho’s group demonstrated the gate-tunable Rashba-Edelstein effect in a multilayer graphene for the first time. The Rahsba-Edelstein effect allows the two-dimensional conduction electrons of graphene to be magnetized by an applied charge current and form a spin current. Furthermore, as the Fermi level of graphene, tuned by gate voltage, moves from the valence to conduction band, the spin current generated by graphene reversed its spin direction.
This spin reversal is useful in the design of low-power-consumption transistors utilizing spins in that it provides the carrier “On” state with spin up holes (or spin down electrons) and the "Off" state with zero net spin polarization at so called “charge neutrality point” where numbers of electrons and holes are equal.
“Our work is the first demonstration of charge-to-spin interconversion in a metallic TMD (transition-metal dichalcogenides) and graphene heterostructure with a spin polarization state controlled by a gate. We expect that the all-electrical spin-switching effect and the reversal of non-equilibrium spin polarization by the application of gate voltage is applicable for the energy-efficient generation and manipulation of spin currents using nonmagnetic van der Waals materials,” explained Professor Cho.
This study (https://pubs.acs.org/doi/10.1021/acsnano.0c01037) was supported by the National Research Foundation of Korea.
Publication:
Lijun Li, Jin Zhang, Gyuho Myeong, Wongil Shin, Hongsik Lim, Boram Kim, Seungho Kim, Taehyeok Jin, Stuart Cavill, Beom Seo Kim, Changyoung Kim, Johannes Lischner, Aires Ferreira, and Sungjae Cho, Gate-Tunable Reversible Rashba−Edelstein Effect in a Few-Layer Graphene/2H-TaS2 Heterostructure at Room Temperature. ACS Nano 2020. Link to download the paper: https://pubs.acs.org/doi/10.1021/acsnano.0c01037
Profile:
Professor Sungjae Cho, PhD
sungjae.cho@kaist.ac.kr
http://qtak.kaist.ac.kr
Department of Physics
Korea Advanced Institute of Science and Technology (KAIST)
https://www.kaist.ac.kr
Daejeon 34141, Korea
2020.05.18 View 9967 -
A Theoretical Boost to Nano-Scale Devices
- Researchers calculate the quasi-Fermi levels in molecular junctions applying an initio approach. -
Semiconductor companies are struggling to develop devices that are mere nanometers in size, and much of the challenge lies in being able to more accurately describe the underlying physics at that nano-scale. But a new computational approach that has been in the works for a decade could break down these barriers.
Devices using semiconductors, from computers to solar cells, have enjoyed tremendous efficiency improvements in the last few decades. Famously, one of the co-founders of Intel, Gordon Moore, observed that the number of transistors in an integrated circuit doubles about every two years—and this ‘Moore’s law’ held true for some time.
In recent years, however, such gains have slowed as firms that attempt to engineer nano-scale transistors hit the limits of miniaturization at the atomic level.
Researchers with the School of Electrical Engineering at KAIST have developed a new approach to the underlying physics of semiconductors.
“With open quantum systems as the main research target of our lab, we were revisiting concepts that had been taken for granted and even appear in standard semiconductor physics textbooks such as the voltage drop in operating semiconductor devices,” said the lead researcher Professor Yong-Hoon Kim. “Questioning how all these concepts could be understood and possibly revised at the nano-scale, it was clear that there was something incomplete about our current understanding.”
“And as the semiconductor chips are being scaled down to the atomic level, coming up with a better theory to describe semiconductor devices has become an urgent task.”
The current understanding states that semiconductors are materials that act like half-way houses between conductors, like copper or steel, and insulators, like rubber or Styrofoam. They sometimes conduct electricity, but not always. This makes them a great material for intentionally controlling the flow of current, which in turn is useful for constructing the simple on/off switches—transistors—that are the foundation of memory and logic devices in computers.
In order to ‘switch on’ a semiconductor, a current or light source is applied, exciting an electron in an atom to jump from what is called a ‘valence band,’ which is filled with electrons, up to the ‘conduction band,’ which is originally unfilled or only partially filled with electrons. Electrons that have jumped up to the conduction band thanks to external stimuli and the remaining ‘holes’ are now able to move about and act as charge carriers to flow electric current.
The physical concept that describes the populations of the electrons in the conduction band and the holes in the valence band and the energy required to make this jump is formulated in terms of the so-called ‘Fermi level.’ For example, you need to know the Fermi levels of the electrons and holes in order to know what amount of energy you are going to get out of a solar cell, including losses.
But the Fermi level concept is only straightforwardly defined so long as a semiconductor device is at equilibrium—sitting on a shelf doing nothing—and the whole point of semiconductor devices is not to leave them on the shelf.
Some 70 years ago, William Shockley, the Nobel Prize-winning co-inventor of the transistor at the Bell Labs, came up with a bit of a theoretical fudge, the ‘quasi-Fermi level,’ or QFL, enabling rough prediction and measurement of the interaction between valence band holes and conduction band electrons, and this has worked pretty well until now.
“But when you are working at the scale of just a few nanometers, the methods to theoretically calculate or experimentally measure the splitting of QFLs were just not available,” said Professor Kim.
This means that at this scale, issues such as errors relating to voltage drop take on much greater significance.
Kim’s team worked for nearly ten years on developing a novel theoretical description of nano-scale quantum electron transport that can replace the standard method—and the software that allows them to put it to use. This involved the further development of a bit of math known as the Density Functional Theory that simplifies the equations describing the interactions of electrons, and which has been very useful in other fields such as high-throughput computational materials discovery.
For the first time, they were able to calculate the QFL splitting, offering a new understanding of the relationship between voltage drop and quantum electron transport in atomic scale devices.
In addition to looking into various interesting non-equilibrium quantum phenomena with their novel methodology, the team is now further developing their software into a computer-aided design tool to be used by semiconductor companies for developing and fabricating advanced semiconductor devices.
The study, featured at the Proceedings of the National Academy of Sciences of the USA on May 12, was supported by the National Research Foundation and the Korea Institute of Science and Technology Information Supercomputing Center.
Image caption: The newly developed formalism and QFL splitting analysis led to new ways of characterizing extremely scaled-down semiconductor devices and the technology computer-aided design (TCAD) of next- generation nano-electronic/energy/bio devices.
Image credit: Yong-Hoon Kim, KAIST
Image usage restrictions: News organizations may use or redistribute this image, with proper attribution, as part of news coverage of this paper only.
Publication:
Juho Lee, Hyeonwoo Yeo, and Yong-Hoon Kim. (2020) ‘Quasi-Fermi level splitting in nanoscale junctions from ab initio.’ Proceedings of the National Academy of Sciences of the United States of America (PNAS), Volume 117, Issue 19, pp.10142-101488. Available online at https://doi.org/10.1073/pnas.1921273117
Profile:
Yong-Hoon Kim
Professor
y.h.kim@kaist.ac.kr
http://nanocore.kaist.ac.kr/
1st-Principles Nano-Device Computing Lab
School of Electrical Engineering
KAIST
(END)
2020.05.15 View 8930 -
Breastfeeding Helps Prevent Mothers from Developing Diabetes after Childbirth
A team of South Korean researchers found that lactation can lower the incidence and reduce the risk of maternal postpartum diabetes. The researchers identified that lactation increases the mass and function of pancreatic beta cells through serotonin production. The team suggested that sustained improvements in pancreatic beta cells, which can last for years even after the cessation of lactation, improve mothers’ metabolic health in addition to providing health benefits for infants.
Pregnancy imposes a substantial metabolic burden on women through weight gain and increased insulin resistance. Various other factors, including a history of gestational diabetes, maternal age, and obesity, further affect women’s risk of progressing to diabetes after delivery, and the risk of postpartum diabetes increases more in women who have had gestational diabetes and/or repeated deliveries.
Diabetes-related complications include damage to blood vessels, which can lead to cardiovascular and cerebrovascular diseases such as heart attack and stroke, and problems with the nerves, eyes, kidneys, and many more. Since diabetes can pose a serious threat to mothers’ metabolic health, the management of maternal metabolic risk factors is important, especially in the peripartum period. Previous epidemiological studies have reported that lactation reduces the risk of postpartum diabetes, but the mechanisms underlying this benefit have remained elusive.
The study, published in Science Translational Medicine on April 29, explains the biology underpinning this observation on the beneficial effects of lactation. Professor Hail Kim from the Graduate School of Medical Science and Engineering at KAIST led and jointly conducted the study in conjunction with researchers from the Seoul National University Bundang Hospital (SNUBH) and Chungnam National University (CNU) in Korea, and the University of California, San Francisco (UCSF) in the US.
In their study, the team observed that the milk-secreting hormone ‘prolactin’ in lactating mothers not only promotes milk production, but also plays a major role in stimulating insulin-secreting pancreatic beta cells that regulate blood glucose in the body.
The researchers also found that ‘serotonin’, known as a chemical that contributes to wellbeing and happiness, is produced in pancreatic beta cells during lactation. Serotonin in pancreatic beta cells act as an antioxidant and reduce oxidative stress, making mothers’ beta cells healthier. Serotonin also induces the proliferation of beta cells, thereby increasing the beta cell mass and helping maintain proper glucose levels.
The research team conducted follow-up examinations on a total of 174 postpartum women, 85 lactated and 99 non-lactated, at two months postpartum and annually thereafter for at least three years. The results demonstrated that mothers who had undergone lactation improved pancreatic beta cell mass and function, and showed improved glucose homeostasis with approximately 20mg/dL lower glucose levels, thereby reducing the risk of postpartum diabetes in women. Surprisingly, this beneficial effect was maintained after the cessation of lactation, for more than three years after delivery.
Professor Kim said, “We are happy to prove that lactation benefits female metabolic health by improving beta cell mass and function as well as glycemic control.”
“Our future studies on the modulation of the molecular serotonergic pathway in accordance with the management of maternal metabolic risk factors may lead to new therapeutics to help prevent mothers from developing metabolic disorders,” he added.
This work was supported by grants from the National Research Foundation (NRF) and the National Research Council of Science and Technology (NST) of Korea, the National Institutes of Health (NIH), the Larry L. Hillblom Foundation, and the Health Fellowship Foundation.
Image credit: Professor Hail Kim, KAIST
Image usage restrictions: News organizations may use or redistribute this image, with proper attribution, as part of news coverage of this paper only.
Publication:
Moon, J. H et al. (2020) ‘Lactation improves pancreatic β cell mass and function through serotonin production.’ Science Translational Medicine, 12, eaay0455. Available online at https://doi.org/10.1126/scitranslmed.aay0455
Profile: Hail Kim, MD, PhD
hailkim@kaist.edu
Associate Professor
Graduate School of Medical Science and Engineering (GSMSE)
Korea Advanced Institute of Science and Technology (KAIST)
Profile: Hak Chul Jang, MD, PhD
janghak@snu.ac.kr
Professor
Division of Endocrinology and Metabolism
Seoul National University Bundang Hospital (SNUBH)
President
Korean Diabetes Association
Profile: Joon Ho Moon, MD, PhD
moonjoonho@gmail.com
Clinical Fellow
Division of Endocrinology and Metabolism
SNUBH
Profile: Hyeongseok Kim, MD, PhD
hskim85kor@gmail.com
Assistant Professor
Chungnam National University (CNU)
Profile: Professor Michael S. German, MD
Michael.German@ucsf.edu
Professor
Diabetes Center
University of California, San Francisco (UCSF)
(END)
2020.04.29 View 19200 -
Long Economic Depressions and Disparities Loom in the Wake of the COVID-19
"Global Cooperation for Managing Data Key to Mitigating the Impacts Around the World"
<Full recorded video of the GSI-IF2020>
The COVID-19 pandemic will lead to long economic depressions around the entire world. Experts predicted that the prevalent inequities among the countries, regions, and individuals will aggravate the economic crisis. However, crises always come with new opportunities and international cooperation and solidarity will help creating a new normal in the post-coronavirus era.
In a very basic but urgent step, global cooperation for managing data is the key to respond to COVID-19 since medicine and healthcare are intertwined with data science, said experts during an online international forum hosted by the Global Strategy Institute at KAIST on April 22.
KAIST launched its think-tank, the Global Strategy Institute (GSI), in February. The GSI aims to identify global issues proactively and help make breakthroughs well aligned with solid science-based policies.
The inaugural forum of the GSI focused on how the COVID-19 pandemic would impact socio-economic, scientific, and political landscapes, under the theme “Global Cooperation in the Coronavirus Era.”
In his opening remarks, KAIST President Sung-Chul Shin stressed that future global governance will be dominated by the power of science and technology. “If we can implement efficient policies together with troubleshooting technology for responding to future crises, we will emerge stronger than before,” he said.
President Shin said ‘the Korean model’, which is being recognized as a shining example for dealing with the pandemic, is the result of collaborations combining the creativity of the private sector, the public sector’s strong infrastructure, and the full support of the citizens. He added, “Without the technological prowess coming from the competent R&D power of Korea, we could not achieve these impressive results.”
“Creative collaboration among the private and public sectors, along with research universities from around the world, will help shore up global resilience against the epidemic. We should work together to build a world of growing prosperity,” President Shin said.
Prime Minister Sye-Kyun Chung, who is in charge of the Central Disaster and Safety Countermeasures Headquarters in Korea, stressed global solidarity in his welcoming remarks, saying that “We need to share information and rely on the strength of our connections, rather than retreating into nationalistic isolation.”
Peter Lee, Vice President of the Microsoft Healthcare, pointed out in his welcoming remarks three critical sectors for global cooperation: medicine and healthcare, public health and prevention, and life and the economy. He emphasized the rule of thumb for managing data, saying that data in these fields should be open, standardized, and shared among countries to combat this global pandemic.
During a keynote session, Director General of the International Vaccine Institute (IVI) Jerome Kim described the challenges that go along with developing a vaccine. Dr. Kim said that only 7% of vaccine candidates go through the clinical trial stages, and it will take five to 10 years to completely prove a new vaccine’s safety after completing three stages of clinical tests.
“It’s very challenging to develop the vaccine for COVID-19 within 12 to 15 months,” said Dr. Kim. He added that 78 out of 115 candidates are currently undergoing clinical trials around the world.
There are five groups, including Moderna, Inovio, Jenner Institute, CanSino, and the Beijing Institute of Biological Products, who are doing clinical trials in phases 1 and 2. “Given the fact that COVID-19 is a totally new type of virus, various stakeholders’ participation, such as the National Immunization Technical Advisory Groups, the WHO, and UNICEF, is needed to work together to benefit the entire world,” he pointed out.
Professor Edward Yoonjae Choi from the Graduate School of AI at KAIST shared how AI and data sciences are being utilized to interpret the major trends of the epidemic. His group mainly focuses on deep learning to model electronic health records (EHR) for disease predictions. Professor Choi said AI and machine learning would be crucial solutions and collaborative research projects will surely accelerate how quickly we can overcome the pandemic.
In addition, Dr. Kijung Shin’s group is interpreting the SIR (Susceptible, Infected, and Recovered) model in Korea to predict the number of infections and when people were infected. However, researchers noticed that they could not see the typical modeling in Korea for predicting the number of infections since the model disregarded the new variable of humans’ efforts to stop the spread the virus.
According to research by Professor Steven Whang’s group on social distancing and face mask distribution among vulnerable age groups, people in their 20s, 60s, and 70s followed the social distancing guidelines the most strictly. The research team analyzed the data provided by SK Telecom in the Gangnam district of Seoul. The data provided on people in their 70s, a group that accounted for half of all fatalities, showed that masks were generally well distributed nationwide.
Dr. Alexandros Papaspyrids, Tertiary Education Industry Director of the Asia region of Microsoft, said that despite all the disadvantages and problems related to remote education, we shouldn’t expect to return to the days before the COVID-19 any time soon. “We should accept the new normal and explore new opportunities in the new educational environment,” he said.
Hongtaek Yong, Deputy Minister at the Office of R&D Policy at the Ministry of Science and ICT presented the Korean government’s disease prevention and response policy and how they tried to mitigate the economic and social impact.
He stressed the government’s fast testing, tracing, and openness for successfully flattening the curve, adding that the government used an ICT-based approach in all aspects of their response. From early this year when the first patient was reported, the government aggressively encouraged the biotech industry to develop diagnostic kits and novel therapeutic medications.
As a result, five companies were able to produce genetic diagnostic reagents through the emergency approval. More notably, four of them are conducting massive R&D projects sponsored by the government and this is the result of the government’s continuous investment in R&D. Korea is the leader in R&D investment among the OECD countries.
According to Yong, the government’s big data project that was launched in 2017 continuously traces the trends of epidemics in Korea. The epidemiological studies based on the paths taken by suspected patients using credit card transaction made the difference in predicting the spread of the coronavirus and implementing countermeasures. The data has been provided to the Korea’s Center for Disease Control (CDC).
“In addition to the epidemics, we have so many other pending issues arising from digital and social equities, un-contact services, and job security. We are very open to collaborate and cooperate with other countries to deal with this global crisis,” Yong said.
During the subsequent panel discussions, David Dollar, a senior fellow at the Brookings Institution, said, “The global economy in the coronavirus era will not have a rapid V-shaped recovery, but rather will fall into a long depression for at least two years.” He pointed out that if countries practice protectionism like they did during the Great Depression, the recession will be even worse. Hence, he urged the international community, especially developed nations, to avoid protectionism, consider the economic difficulties of developing countries, and provide them with financial support.
Co-Director of the Center for Universal Education at the Brookings Institution Rebecca Winthrop raised concerns over the recent shift to online teaching and learning, claiming that insufficient infrastructures in low-income families in developing nations are already causing added educational disparities and provoking the inequity issue around the world. “The ways to provide quality education equally through faster and more effective means should be studied,” she said.
Professor Joungho Kim, the director of the KAIST GSI and the forum’s organizer, concluded the event by saying that this forum will be a valuable resource for everyone who is providing assistance to those in need, both during and after the COVID-19 pandemic.
(END)
2020.04.22 View 21428 -
14-Day Drawing Challenge Helps Maintain a Sense of Connection Amid Prolonged Social Distancing
- “You need space, but you also need connections.” -
Schools and workplaces have closed and people are staying at home around the globe. Governments across the world have urged their people to keep a distance from others as a measure to slow the spread of the pandemic.
With the Korean government’s decision to extend the intensive social distancing campaign until at least April 19, people in Korea are advised to avoid nonessential trips, public facilities, and social gatherings for another two weeks or so.
This unprecedented prolonged social distancing drive leads people to feel fatigue and frustration. Such emotional stress is worse for those who live alone in a foreign country.
The International Scholar and Student Services (ISSS) Team at KAIST has been working around the clock to build a dedicated COVID-19 Mental Health Support Service to support the university’s international community on campus and abroad and help get them connected online.
As the COVID-19 situation lingers, there has been a growing demand for mental health support from many KAIST international members including 299 students who have been staying in Korea on their own and away from their families, as well as from those who could not return to campus from their overseas homes.
In response to this, the KAIST ISSS Team has been offering some special online events and programs that can help the KAIST international community stay feeling connected whereever they are, while still keeping a safe distance from each other.
For instance, the team is running an art-therapy program called ‘The 14-day Drawing Challenge’ March 30 through April 12. This program is online and individual-based, so it does not require any physical contact between participants.
Each participant is asked to draw a picture at home using the daily topics previously set by the ISSS Team over 14 days. The topics include (Day 1) self-portrait, (Day 2) spring flowers, (Day 3) if you could become anything…, (Day 4) funniest memory you have, (Day 5) animals at KAIST, (Day 6) something you love, (Day 7) country or city you want to visit, (Day 8) what’s for dinner? (Day 9) person you miss, (Day 10) your favorite place at KAIST, (Day 11) your feeling today, (Day 12) things in your favorite color, (Day 13) song lyrics, and (Day 14) your future self in 10 years.
Once all 14 pieces have been completed, submissions can be made online by sending an e-mail to the ISSS Team after scanning or taking a photo of each drawing. Selected submissions will be awarded small prizes for participation and shared through the university’s official website and SNS channels.
“All the participants need is paper, coloring tools, and their creativity and imagination. They don’t have to be a great artist to join this challenge. There is no right or wrong or good or bad. They just need to have fun drawing every day for two weeks, ease their coronavirus anxiety, and remain emotionally stable just like they did back in the normal days,” said Su-yeon Ahn, the manager of the KAIST ISSS Team. She added, “In times like these, you need space, but you also need connections. Our team wants our international students, professors, and researchers to build strong connections with each other, even online.”
Katherine Michelle Pena Santana, an M.S. candidate from the Department of Industrial and Systems Engineering who is taking part in ‘The 14-day Drawing Challenge,’ looked back and said, “Lately with the new coronavirus spreading around Korea and the entire world, I was feeling very anxious. I didn't get out of my room and lived by just looking at the same walls and creating some kind of a psychological burden on myself.”
Santana added that these kinds of activities could give many foreign members of KAIST an opportunity to not only relieve fear and stress, but also share each other’s experiences dealing with this pandemic. She explained that this is why she decided to participate in this challenge.
An undergraduate student from the Department of Physics, Ada Carpenter, appreciated the KAIST ISSS Team’s efforts to provide a variety of special online mental health support services to help the university’s international community socialize, while strictly following the government’s guidelines for social distancing. She expressed excitement about participating and said, “I’m so looking forward to the challenge of things that I wouldn’t normally draw.”
< Short Self-interview Video Clip Filmed by Ada Carpenter >
The COVID-19 Mental Health Support Service by the KAIST ISSS Team will be continually updated with new information and enhanced with other tools and support over the coming weeks and months. Some of the upcoming events and programs include ‘The Online Guitar Lessons’, ‘The Growing Houseplants Challenge’, and ‘The Any Song Challenge*’.
* The song titled “Any Song” by Korean rapper Zico has been gaining attention on social media thanks to many celebrities taking on the ‘Any Song Challenge’, performing a short dance to the chorus of the song and sharing it on social media.
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2020.04.08 View 10619 -
Former Minister of Science and Technology Woo Sik Kim Elected as New Chairman of Board of Trustees
Dr. Woo Sik Kim, former Minister of Science and Technology and Deputy Prime Minister, was elected as the new chairman of the KAIST Board of Trustees on March 26. Dr. Kim will succeed Chairman Jang-Mu Lee, whose three-year term expired last month.
Dr. Kim is a chemical engineering professor who spent most of his academic career at Yonsei University from 1968. In 2000, he held the office of president of Yonsei University for four years before moving to the Presidential Office of President Roh Moo-Hyun as his chief of staff in 2004. After serving in the Blue House for two years, he served as the Minister of Science and Technology from 2006 to 2008.
An emeritus fellow of the National Academy of Engineering of Korea (NAEK), Chairman Kim also taught at KAIST as an invited distinguished professor from 2008 to 2010. He is currently the chairman of the Creativity Engineering Institute (CEI).
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2020.04.06 View 12332 -
COVID-19 Update: Reaching Out to Help Local Schools’ Online Classes
After the Ministry of Education decided that all schools would conduct online classes from April 9, schools began to ramp up online education tools and systems. On March 30, the Ministry announced a three-phased opening for the schools, putting online classes for third-year middle and high school students first. The online classes will expand to first and second-year middle and high schoolers and the upper grades of elementary schools on April 16, followed by first to third graders of elementary schools on April 20.
Although some schools have already introduced online teaching and learning into the curriculum, most schools are still unprepared, raising concerns over possible educational disparities caused by insufficient infrastructures and a lack of training for teachers.
To counter these issues, KAIST rolled up its sleeves to help teachers from 38 local middle and high schools in the Yuseong District of Daejeon better prepare for their interactive online classes by providing a special training course from April 7 through 29. Following the course, approximately 40 undergraduate and graduate students will be assigned to schools to help them set up and better utilize the online educational program.
On April 3, Professor Youngsun Kwon, the Dean of KAIST Academy and the Director of the Center for Excellence in Learning and Teaching, gave a two-hour online interactive tutorial session on the utilization of the real-time video conferencing platform ‘Zoom’ for online classes. He shared best practices for checking attendance, running classes, and giving and marking quizzes and assignments. A total of 102 local middle and high school teachers attended this session.
“We feel very fortunate to reach out to teachers who are so passionate about learning online education methodology. We were pleasantly surprised to see this many educators show up for the tutorial session,” said Dean Kwon. He also appreciated KAIST students’ strong interests and support in the community outreach project in response to COVID-19 during these challenging times when social distancing is so critical.
He said more than 150 student volunteers signed up for this project 10 hours after his office posted the opening for volunteers on the KAIST intranet. “We will help front-line school teachers, strictly following the government’s guidelines for social distancing,” he added.
The students’ online class support group will provide additional help to schools that are inexperienced users of Zoom. The students will be those who are very familiar with online lectures using Zoom, and are fully acquainted with how to operate them. One or two of the students will be assigned to each school that requests support, and will directly help solve complications that stem from preparing and running the classes through online measures for safety reasons. The expenses for the support group’s activities will be fully covered by KAIST, and the period of support may be extended upon request.
KAIST has been offering approximately 1,200 courses remotely since the spring semester opened on March 16 and will do so until the COVID-19 situation stabilizes. Along with the provision of pre-recorded one-way lecture contents, real-time two-way lessons are being delivered through various video conferencing platforms including Zoom, YouTube Live, and Microsoft Teams. There were both minor and major technical issues at the beginning of the semester, caused by the instability of servers and system overloads as well as from users being inexperienced with the tools and systems. However, the class procedures have gradually stabilized and are now running better.
KAIST President Sung-Chul Shin said, “As the COVID-19 situation lingers, this is a more difficult time than ever, where all educational establishments and educators must quickly learn and apply new methods of education, often in insufficient preparation conditions.” He added, “KAIST will provide support for secondary schools in the region to quickly resolve the inconveniences caused by new users of online classes so that they may provide high-quality education.”
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2020.04.06 View 7979 -
Highly Efficient and Stable Double Layer Solar Cell Developed
Solar cells convert light into energy, but they can be inefficient and vulnerable to the environment, degrading with, ironically, too much light or other factors, including moisture and low temperature. An international research team has developed a new type of solar cell that can both withstand environmental hazards and is 26.7% efficient in power conversion.
They published their results on March 26 in Science.
The researchers, led by Byungha Shin, a professor from the Department of Materials Science and Engineering at KAIST, focused on developing a new class of light-absorbing material, called a wide bandgap perovskite. The material has a highly effective crystal structure that can process the power needs, but it can become problematic when exposed to environmental hazards, such as moisture. Researchers have made some progress increasing the efficiency of solar cells based on perovskite, but the material has greater potential than what was previously achieved.
To achieve better performance, Shin and his team built a double layer solar cell, called tandem, in which two or more light absorbers are stacked together to better utilize solar energy. To use perovskite in these tandem devices, the scientists modified the material’s optical property, which allows it to absorb a wider range of solar energy. Without the adjustment, the material is not as useful in achieving high performing tandem solar cells. The modification of the optical property of perovskite, however, comes with a penalty — the material becomes hugely vulnerable to the environment, in particular, to light.
To counteract the wide bandgap perovskite’s delicate nature, the researchers engineered combinations of molecules composing a two-dimensional layer in the perovskite, stabilizing the solar cells.
“We developed a high-quality wide bandgap perovskite material and, in combination with silicon solar cells, achieved world-class perovskite-silicon tandem cells,” Shin said.
The development was only possible due to the engineering method, in which the mixing ratio of the molecules building the two-dimensional layer are carefully controlled. In this case, the perovskite material not only improved efficiency of the resulting solar cell but also gained durability, retaining 80% of its initial power conversion capability even after 1,000 hours of continuous illumination. This is the first time such a high efficiency has been achieved with a wide bandgap perovskite single layer alone, according to Shin.
“Such high-efficiency wide bandgap perovskite is an essential technology for achieving ultra-high efficiency of perovskite-silicon tandem (double layer) solar cells,” Shin said. “The results also show the importance of bandgap matching of upper and lower cells in these tandem solar cells.”
The researchers, having stabilized the wide bandgap perovskite material, are now focused on developing even more efficient tandem solar cells that are expected to have more than 30% of power conversion efficiency, something that no one has achieved yet,
“Our ultimate goal is to develop ultra-high-efficiency tandem solar cells that contribute to the increase of shared solar energy among all energy sources,” Shin said. “We want to contribute to making the planet healthier.”
This work was supported by the National Research Foundation of Korea, the Korea Institute of Energy Technology Evaluation and Planning, the Ministry of Trade Industry and Energy of Korea, and the U.S. Department of Energy.
Other contributors include Daehan Kim, Jekyung Kim, Passarut Boonmongkolras, Seong Ryul Pae and Minkyu Kim, all of whom affiliated with the Department of Materials Science and Engineering at KAIST. Other authors include Byron W. Larson, Sean P. Dunfield, Chuanxiao Xiao, Jinhui Tong, Fei Zhang, Joseph J. Berry, Kai Zhu and Dong Hoe Kim, all of who are affiliated with the National Renewable Energy Laboratory in Colorado. Dunfield is also affiliated with the Materials Science and Engineering Program at the University of Colorado; Berry is also affiliated with the Department of Physics and the Renewable and Sustainable Energy Institute at the University of Colorado Boulder; and Kim is also affiliated with the Department of Nanotechnology and Advanced Materials Engineering at Sejong University. Hee Joon Jung and Vinayak Dravid of the Department of Materials Science and Engineering at Northwestern University; Ik Jae Park, Su Geun Ji and Jin Young Kim of the Department of Materials Science and Engineering at Seoul National University; and Seok Beom Kang of the Department of Nanotechnology and Advanced Materials Engineering of Sejong University also contributed.
Image credit: Professor Byungha Shin, KAIST
Image usage restrictions: News organizations may use or redistribute this image, with proper attribution, as part of news coverage of this paper only.
Publication: Kim et al. (2020) “Efficient, stable silicon tandem cells enabled by anion-engineered wide band gap perovskites”. Science. Available online at https://doi.org/10.1126/science.aba3433
Profile:
Byungha Shin
Professor
byungha@kaist.ac.kr
http://energymatlab.kaist.ac.kr/
Department of Materials Science and Engineering
KAIST
Profile:
Daehan Kim
Ph.D. Candidate
zxzx4592@kaist.ac.kr
http://energymatlab.kaist.ac.kr/
Department of Materials Science and Engineering
KAIST
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2020.03.27 View 20499 -
Recyclable Nano-Fiber Filtered Face Masks a Boon for Supply Fiasco
Wearing a face mask is a common sight in Korea during the COVID-19 outbreak. Due to the overwhelming demand, last week the government started to ration two masks per person per week, as a drastic measure to address the supply fiasco.
The face masks most commonly used are disposable ones, originally made for filtering out up to 94 or 95 percent of fine dust, referred to as N94 or N95 masks.
A KAIST research team announced that they have developed a nano-filter that maintains excellent filtering efficiency even after hand washing through the development of proprietary technology that aligns nanofibers with a diameter of 100~500 nm in orthogonal or unidirectional directions. This reusable nano-filtered face mask could help to relieve the challenges arising from the supply shortage of face masks.
Professor Il-Doo Kim’s nano-fiber filtered mask will maintain its sturdy frame and filtering function even after being washed more than 20 times. Professor Kim, who has continued to study the filtering of fine dust using nano-filters, is now awaiting final approval from the Ministry of Food and Drug Safety to bring his product into the market.
Professor Kim used an insulation block electrospinning process to manufacture orthogonal nanofibers by controlling the alignment of nanofibers. This structure can minimize delivering of the pressure toward the air filter and maximize the filtration efficiency, which is different from existing disposable masks without nano-fibers.
Existing masks also fail to maintain their air filtering function because their electrostatic function disappears when exposed to water. Thus, their filtering efficiency is reduced significantly, making it almost impossible to reuse them. However, this nano-fiber design was proven to be water resistant with more than 94% filtering efficiency in 20 repeated bactericidal tests with ethanol. The nano-fiber mask also showed no deformation in its nano-membrane structure despite the 20 hand washes. In particular, it was confirmed that there were no deformations in the membrane, even after soaking in ethanol more than three hours.
Professor Kim said, “We believe that this mask can be reusable for about a month even after washing in ethanol. The inner filter can also be replaced.” He added, “We found that the mask filters out up to 80 percent of 600-nanometer particles even after undergoing a bending test more than 4,000 times.”
Professor Kim established his startup company, the “Kim Il-Doo Research Institute,” last February. It can currently produce 1,500 nano-fiber filters per day.
2020.03.17 View 22836