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International Students Start a New Semester at KAIST
(International students during a campus tour)
The 2017 fall semester began on August 28 and new and returning students are filling the campus. Our international students are one of the reasons the campus is becoming more dynamic and energetic.
It was easy to see groups of smiling international students walking around the campus. Every semester, KAIST welcomes hundreds of students from around the world to give them the opportunity to study at a world-leading university in science and technology.
This semester, approximately 150 students in degree-seeking programs and 220 exchange students from a total of 74 countries, including Germany, the United States, and France entered KAIST.
(Frederik Hansen, a student from DTU)
Frederik Hansen is an exchange student who came to KAIST this semester from Copenhagen, Denmark. He completed the undergraduate program at the Technical University of Denmark (DTU) and is now pursuing a master’s degree.
He decided to join KAIST because he felt the university is up-to-date with subjects in his field of interest.
Frederik, who majored in mechanical engineering, looks forward taking classes related to robotics and solid mechanics. Noting that it’s his first time visiting Asia, he hopes to experience and learn about Korean culture.
In an effort to help foreign students’ soft landing in KAIST, the International Office held a series of orientation programs over three days. The buddy program provides international freshmen with an opportunity to make Korean friends for a more successful life at KAIST, while giving domestic students a chance to learn about different cultures and perhaps build on the global capacity required for becoming a global leader. Information sessions also provided educational information that can support international students living in KAIST. Finally, the counseling program gives information about the KAIST counseling center and ISSS (International Scholar and Student Service). It provides a psychometric test service to those who wish to take it.
If you are interested in pursuing academic programs at KAIST, please visit the International Office via http://io.kaist.ac.kr/index.do .
2017.08.30 View 5653 -
2017 KAIST Tech Fair to Showcase Ten Cutting-Edge Technologies
KAIST will showcase the ten most cutting-edge technologies developed by KAIST faculty and researchers at the 2017 KAIST Tech Fair. The fair will be held on September 12 at the COEX in Seoul. The fair will bring companies, venture capitalists, and tech consultants from around the country to learn about the most commercially potential technology from KAIST.
The ten technologies, all already patented, will be highly relevant for the new industrial trends summed up by the Fourth Industrial Revolution. They include the fields of ICT, unmanned transportation, AI, robotics, IoT, nano, and big data.
The Technology Evaluation Committee, comprised of the heads of the departments at KAIST, patent lawyers, and venture capitalists, selected the ten technologies based on their applicability, innovativeness, and marketability. The selectees will be provided with various commercialization support and services including the manufacturing of prototypes, marketing consultation at home and abroad, as well as handling IPR issues, among others.
KAIST will hold an information session as well as consultations for successful technology commercialization as one of the innovative plans proposed by the KAIST President Sung-Chul Shin. This session will invite 200 entrepreneurs who are interested in the selected technologies.
Associate Vice President of University-Industry Cooperation Kyung Cheol Choi said, “Starting with the selection of 2017 top ten crucial technologies, KAIST will continue supporting technology marketing as well as its successful transfer. KAIST will make effort to carry out university-industry cooperation and find core patent technologies and project ideas in order to stimulate technology commercialization.”
The list of the ten critical patent technologies selected by KAIST is as follows:
▶ Catalyst-Decorated Nanofiber Sensor for Health Monitoring
By Professor Il-Doo Kim (Department of Materials Science and Engineering)
Human breath carries diverse components of diseases such as asthma, lung cancer, type 1 diabetes mellitus, and halitosis. Thus, it is possible to analyze exhaled breath very rapidly with a simple analyzing process and it can detect trace changes in exhaled breath components, which trigger diseases.
The research team developed highly sensitive and selective chemical gas sensors that can detect specific disease, using protein-encapsulated nanocatalysts. They can diagnose certain diseases by analyzing human exhaled breath. This technology enables the early monitoring of various diseases through pattern recognition of biomarker gases associated with the diseases in human exhalation.
The established sensing libraries can detect biomarker species with high sensitivity and selectivity. The team hopes that the new and innovative breath gas analysis platform will be very helpful for reducing medical expenditures and the continuous monitoring of physical conditions.
# Detection of environmental toxic gases, monitoring of body health condition
Figure (a) Mobile device integrated with nanofiber based MEMS sensorsFigure (b) Exhaled breath pattern recognition: principle component analysis for the accurate detection of acetone, hydrogen sulfide, and toluene gases
▶ Technology for a Cancer Cure Using Big Data and Simulating Biological Network By Professor Kwang-Hyun Cho (Department of Bio and Brain Engineering)
The complex and heterogeneous nature of cancer, which results in highly variable drug responses, is a major obstacle in curing cancer. Previous methods to predict drug responses mostly focus on the static analysis of genome-wide alternations, resulting in a limitation for the understanding of cancer heterogeneity and its variable responses.
The research team used a method to integrate cancer genomics data with the dynamics of biological networks for drug response prediction and to design of effective drug combination. It provides a computational framework for evaluating drug efficacies and synergistic effects by combining the attractor landscape analysis of a biological network with the genomic alteration profiles of cancer cells.
This technology can reduce the cost of drug development by predicting drug responses and help selecting more effective new drug targets in consideration of the overall cellular response landscape. It can also provide comprehensive insight into the mechanistic origin of variable drug responses. The patent technology can be applicable to designing more effective and cancer-specific combination therapies.
# Development of targeted anticancer drugs, genetic testing
Figure (a) The computational prediction of drug responses using attractor landscape analysis of network dynamics
▶ Highly Stretchable, Wearable Strain SensorBy Professor O Ok Park (Department of Chemical and Biomolecular Engineering)
Conventional materials for strain sensor are metals or semiconductors, but these materials show a limited range of strain. To improve the stretchability of conventional materials, several projects have been done using novel materials with a high aspect ratio; nevertheless, these projects encountered problems, including complex and expensive processes, poor scalable features, and low controllability of the sensitivity in the manufacturing step.
The research team used a layer-by-layer assembly technique to control the sensitivity of the sensor in a facile and inexpensive method. By using stretchable yarn as a substrate, the graphene strain sensor gained more stretchability.
Through the newly-patented technology, the graphene strain sensor can be fabricated using an all-solution process; therefore, the sensitivity of the sensor can be easily controlled with a repetitive cycle of the coating process. The size of this sensor can be controlled as well, because it depends only on the size of coated substrate.
# Wearable strain sensor, planar strain sensor
Figure (a) Nylon-covered rubber yarn showing linear relationship between the applied strain load and its resistance change
Figure (b) Wool yarn showing an inverse relation of resistance with the applied strain load
▶ Chip & Flash Memory Data Security DeviceBy Professor Yang-Kyu Choi (School of Electrical Engineering)
Using software-based security methods can lead to having problems related to the backtracking of a security function through reverse engineering, the replication of an input value, and the forgery and modification of software. These problems should not be neglected, especially as people are increasingly recognizing the importance of personal information.
To meet the growing demands for new security methods for constructing a more perfect security system, the research team developed a hardware-based security device as well as methods for a higher level of security in the era of IoTs. The principles of the technologies are based on nanotechnology, such as mechanical deformation in a nanowire, electrical degradation in a field-effect transistor (FET), and thermal data erasing stored in the charge trap layer in flash memory. Hence, the security states are extremely safe, compared with software-based security methods and cannot be reverse-engineered by unauthorized users.
This patented technology can be used to improve the security level of logic circuits and flash memory against unauthorized users.
# Financial businesses, the defense industry, private electronics including smartphones, tablets and PCs, electronics for missions in extreme environments
Figure (a) Application for a high level of security in a logic circuit
▶ A Bio-Healthcare Device for Neuroimaging
By Professor Hyeonmin Bae (School of Electrical Engineering)There are no portable brain imaging devices and, as a result, brain diseases are often diagnosed after irreversible symptoms appeared. This can also be linked to an increase in social expenditures as a society ages.
A near-infrared spectroscopy neuroimaging device for functional brain imaging, NIRSIT, utilizes light to detect hemodynamic changes in cerebral blood flow and visualizes brain activation regions in the prefrontal area of the brain in real time.
Unlike any other existing brain imaging devices (i.e. fMRI and conventional fNIRS), NIRSIT has improved its spatial resolution while maintaining complete portability.
Furthermore, NIRSIT is probably the one and only portable and wireless NIRS device, designed to be used for brain research and clinical purposes. A software application allows the raw data extracted from the hemodynamic changes in the brain to be shown in real time on a tablet wirelessly connected to NIRSIT.
Thanks to its easy-to-use features and user-friendly design, both in hardware and in software, NIRSIT will surely set a new paradigm in the brain research and healthcare fields.
# Concussion analysis, wearable stroke monitoring, CPR monitoring, Alzheimer’s disease, neuro rehabilitation, determination of brain death
Figure (a) Image of NIRSIT, Figure (b) Neuroimaging using NIRSIT
▶ Technology for Virtual Creatures with Digitally-Emotional DNA of UsersBy Professor Jong-Hwan Kim (School of Electrical Engineering)
Currently, a large number of IT companies around the world are trying to develop a system that can offer active and emotional services and the interface method is one of the most important issues.
Although most of the existing software agents are equipped with virtual faces and voices, they do not possess a personality similar to humans. Having various personalities, like human beings, can be a charming point for users, which then leads them to have higher satisfaction with the product.
Dr. Kim’s research team developed Darwin C (Digital Agent Reconstruction with Intelligence and Natural Character), a digital agent software that provides an optimized emotional service based on personal big data, such as the user’s conversations, locations, photos, music, etc., collected from smart devices.
With this technology, the digital DNAs of a user (i.e. appearance, voice, and personality DNA) is extracted from personal data stored on various smart devices. Based on the extracted digital DNA, a 3-D software agent can be formed in a smartphone, which characterizes an individual that the user hopes to meet, such as parents, spouse, grandchild, or a celebrity.
The software agents will be expanded from Android devices to home appliances. The team expected that this technology can help customers who want to understand more about a friend or form and maintain interpersonal relations.
# Entertainment, hardware robots for education, healthcare curing depression and loneliness
Figure (a) Overview of the DarwinC technology, Figure (b) Structure of digital DNA
▶ Laser-Integrated Precision Metrological System Technology for Smart Factories By Professor Seung-woo Kim (Department of Mechanical Engineering)
In optical distance metrology, the time-of-flight method of using light pulses permits measuring distances over extensive ranges. However, the measurement precision reaches just a few tens of millimeters at most, mainly because the responsivity of the photodetectors available today is limited to the picosecond range. In addition, one device can measure only one target. For these reasons, a novel technology was devised to overcome the traditional limits of time-of-flight measurement.
This patented technology uses a highly precise, laser-integrated distance measurement system for diagnosing large machines and smart factories. This technology was devised to handle the status (e.g. position, 3-D coordinate, and thermal deformation) of multiple targets simultaneously. It is called the multi-target distance meter (MDM) and was constructed by combining a nonlinear optical crystal with a pair of femtosecond lasers.
This technology is able to measure the distances to multiple targets with a single piece of equipment, and it can easily extend the number of targets by just adding beam-splitting devices. Not only does the technology help by reducing cost and complexity, it also enables real-time quality control in the manufacturing industry.
# Real-time on-axis position inspection of a multiple-lens assembly, long-term thermal displacement monitoring of a large, precise machine, 3-D motion control of a mobile vehicle
Figure (a) Conceptual image of smart factory monitoring using laser-integrated precision metrological system technology
▶ SLAM Technology for Autonomous Robot Navigation in a Dynamic Indoor/Outdoor EnvironmentBy Professor Hyun Myung (Department of Civil & Environmental Engineering)
Dr. Myung’s research team developed SLAM (Simultaneous Localization and Mapping) technology for autonomous robot navigation in dynamic indoor/outdoor environments. Two methods were applied to this technology: a hierarchical graph structure-based 3-D high resolution map building method using a low-cost 2D laser scanner and a magnetic field-based localization method for feature-poor environments.
Existing technology required expensive sensors for outdoor environment. The localization and mapping technique were also not very accurate, especially in dynamic environments. The team wanted to provide robust SLAM in low and high dynamic object environments using the fusion of low-cost sensors, such as magnetics, 2-D LiDAR, and camera sensors.
Through this technology, the accuracy of localization and mapping could be increased to within 10cm, using low-cost sensors. Also, it facilitates localization and mapping even in feature-poor environments.
# Autonomous robot navigation in warehouses, autonomous navigation of self-driving cars, autonomous navigation of AGVs (Automated Guided Vehicles) in smart factories
Figure (a) Built outdoor 3-D mappring using a mobile robot with tilted 2-D LiDAR sensor, Figure (b) Mobile robot system for GPS-less mappring
▶ Technology for Optimizing 5G Beamforming ICBy Songcheol Hong (School of Electrical Engineering)
Dr. Hong’s team introduced a new structure for low-power, subminiature, and highly-linear beamforming IC technology. The patent used in this technology reduced the chip size and the direct current (DC) power dissipations drastically, allowing it to make mmWave beamforming antennas.
Beam-forming technology has emerged as an important area in the field of 5G communications and radar systems. It facilitates communication and signal detection with very low RF power.
The patents can be applied to 5G communication beam-forming ICs and antenna modules in mobile terminals, base stations and terminals in the automotive field. Moreover, they can be used in various mmWave radar systems for automobiles, drones, human computer interfaces, and indoor positioning.
# 5G V2X, IoTs, virtual reality
Figure (a) Active phased array system
▶ Beam Division Multiple Access TechnologyBy Professor Dong Ho Cho (School of Electrical Engineering)
Using a 5G network, a communication infrastructure for supporting high-speed, real-time services requires new technologies that enable 4x4 MIMO transmissions within beam-based wireless systems in a new frequency band and improves spectral efficiency more than ten times compared to LTE in domestic and overseas mobile communication carriers and related industries.
P2BDMA, a pattern or polarization beam division multiple access technology, is a core technology for addressing this demand for 5G networks as it enables 4x4 MIMO transmissions in mmWave frequency bands by utilizing the pattern polarization characteristic of radio waves.
The research team upgraded BDMA technology in which the same frequency resource is reused in more than two spaces by using beamforming. This technology increases the degree of freedom (DOF) of wireless communication channels, and thereby improves the achievable data transmission rate by employing multiple pattern/polarization antennas in the conventional BDMA system. The P2BDMA technique has the advantage of eliminating the frequency shortage problem and increasing the transmission speed while using the wide frequency band in a more efficient manner.
The team expects that this technology will alleviate the frequency shortage problem and CAPEX/OPEX of domestic mobile telecommunication companies, support an increase in sales for related equipment makers to make it internationally competitive, and further play a central role in providing high-speed transmission rates to a large number of IoT devices in the future IoT era.
# Autonomous vehicle, communication infrastructure, mobile access system
Figure (a) Concept of P2BDMA technology
2017.08.30 View 14857 -
The Medici Effect: Highly Flexible, Wearable Displays Born in KAIST
(Ph.D. candidate Seungyeop Choi)
How do you feel when technology you saw in a movie is made into reality? Collaboration between the electrical engineering and textile industries has made TVs or smartphone screens displaying on clothing a reality.
A research team led by Professor Kyung Cheol Choi at the School of Electrical Engineering presented wearable displays for various applications including fashion, IT, and healthcare. Integrating OLED (organic light-emitting diode) into fabrics, the team developed the most highly flexible and reliable technology for wearable displays in the world.
Recently, information displays have become increasingly important as they construct the external part of smart devices for the next generation. As world trends are focusing on the Internet of Things (IoTs) and wearable technology, the team drew a lot of attention by making great progress towards commercializing clothing-shaped ‘wearable displays’.
The research for realizing displays on clothing gained considerable attention from academia as well as industry when research on luminescence formed in fabrics was introduced in 2011; however, there was no technology for commercializing it due to its surface roughness and flexibility.
Because of this technical limitation, clothing-shaped wearable displays were thought to be unreachable technology. However, the KAIST team recently succeeded in developing the world’s most highly efficient, light-emitting clothes that can be commercialized.
The research team used two different approaches, fabric-type and fiber-type, in order to realize clothing-shaped wearable displays. In 2015, the team successfully laminated a thin planarization sheet thermally onto fabric to form a surface that is compatible with the OLEDs approximately 200 hundred nanometers thick. Also, the team reported their research outcomes on enhancing the reliability of operating fiber-based OLEDs. In 2016, the team introduced a dip-coating method, capable of uniformly depositing layers, to develop polymer light-emitting diodes, which show high luminance even on thin fabric.
Based on the research performance in 2015 and 2016, Ph.D. candidate Seungyeop Choi took the lead in the research team and succeeded in realizing fabric-based OLEDs, showing high luminance and efficiency while maintaining the flexibility of the fabric.
The long-term reliability of this wearable device that has the world’s best electrical and optical characteristics was verified through their self-developed, organic and inorganic encapsulation technology. According to the team, their wearable device facilitates the operation of OLEDs even at a bending radius of 2mm.
According to Choi, “Having wavy structures and empty spaces, fiber plays a significant role in lowering the mechanical stress on the OLEDs.”
“Screen displayed on our daily clothing is no longer a future technology,” said Professor Choi. “Light-emitting clothes will have considerable influence on not only the e-textile industry but also the automobile and healthcare industries.”
Moreover, the research team remarked, “It means a lot to realize clothing-shaped OLEDs that have the world’s best luminance and efficiency. It is the most flexible fabric-based light-emitting device among those reported. Moreover, noting that this research carried out an in-depth analysis of the mechanical characteristics of the clothing-spared, light-emitting device, the research performance will become a guideline for developing the fabric-based electronics industry.”
This research was funded by the Ministry of Trade, Industry and Energy and collaborated with KOLON Glotech, INC. The research performance was published in Scientific Reports in July.
(OLEDs operating in fabrics)
(Current-voltage-luminance and efficiency of the highly flexible, fabric-based OLEDs;Image of OLEDs after repetitive bending tests;Verification of flexibility through mechanical simulation)
2017.08.24 View 13790 -
Global ITTP Graduates 12 Public Officials from 11 Countries
The 18th Global Information and Telecommunication Technology Program (ITTP) graduated 12 public officials from 11 countries in a commencement ceremony held on August 23.
Distinguished guests, faculty, and family of graduates including President Sung-Chul Shin, the Chair of the School of Business and Technology Youngsun Kown, and the Director of Global ITTP Jaejung Rho attended the commencement. Ghana Ambassador Joseph Agoe, Mrs. Lyudmila Fen, the spouse of Uzbekistan Ambassador Vitali Fen, and other dignitaries came to congratulate the 12 master’s students on their successful graduation.
The Global ITTP was launched in 2006 and offers customized master’s and doctoral degree programs to elite public officials from diverse countries on information and communication technology. This program plays a vital role for transferring Korea’s advanced ICT to countries whose industries are in the budding stages. Since 2006, the program has produced 181 alumni (48 PhDs and 133 masters) from 60 countries.
In his congratulatory message during the ceremony, President Shin congratulated the graduates on the long journey they had been through while completing their courses and welcomed the newest addition of KAIST 12 alumni.
“Back in the 1960s, Korea was one of the poorest countries in the world. Korea’s GDP stood at less than 100 US dollars. Through it all, Korean companies are now taking the lead in the global high-tech market, emerging as movers and shakers. I believe that ‘VIP’ changed it all; in other words, visionary leaders, innovative ideas, and passionate people all combined to make the difference in Korea,” said President Shin.
He also shared a new formula for success in the wake of the new industrial environment of the Fourth Industrial Revolution with the graduates who will soon begin a new ambitious professional journey in their countries. “I think Innovation, Collaboration, and Speed will be the key words to make a difference in every sector of each and every country in this dynamic new era. When making a national development strategies, please keep in mind ‘ICS’ for the development of your country as well as the world’s sustainable development.”
Finally, he said, “As a KAIST alumnus, always be sincere wherever you work and whatever you do during your service. I advise you to become a leader who is doing one’s best at all times.”
☞ Link to the 18th commencement address
2017.08.24 View 6084 -
Solutal Marangoni Flows of Miscible Liquid Drive Transport without Surface Contamination
(Professor Hyoungsoo Kim, Department of Mechanical Engineering, KAIST)
A research team led by Hyoungsoo Kim, a professor of Mechanical Engineering at KAIST, succeeded in quantifying the phenomenon called, the Marangoni effect, which occurs at the interface between alcohol and water. It is expected that this finding will be a valuable resource used for effectively removing impurities from a surface fluid without any contamination, and developing materials that can replace surfactants.
This research, co-conducted with a research team led by Professor Howard A. Stone at Princeton University, was published online in Nature Physics on July 31.
The Marangoni effect, also known as tears of wine, is generated when two fluids having a different surface tension meet, causing finite mixing, spreading time and length scale. Typically, people believe that infinitely miscible liquids immediately mix together; however, it is not always true according to this paper.
The typical surface tension of alcohol is three times lower than that of water, and this different surface tension generates the Marangoni-driven convection flow at the interface of the two liquids. In addition, there is a certain amount of time required for them to mix.
This phenomenon has been discussed many times since it was discovered in early the 20th century, yet there was a limit to quantifying and explaining it.
Professor Kim, considering the mixing and spreading mechanism, used various flow visualization techniques and equipment for capturing high speed images in his experiment.
Through the flow visualization methods, the team succeeded in quantifying and explaining the complex, physicochemical phenomenon generated between water and alcohol. Moreover, they developed a theoretical model to predict the physicochemical hydrodynamic phenomena.
The theoretical model can predict the speed of Marangoni-driven convection flow, the area of a drop of alcohol and the time required to develop the flow field. Hence, this model can map out types of materials (e.g., alcohol) and the volume of a drop of liquid as applicable to target a specific situation.
Moreover, the research team believes that the interfacial flow enables the driving of bulk flows and that it can be a source of technology for effectively delivering drugs and removing impurities from a surface of substance without causing secondary contamination.
Above all, the results show a possibility for replacing surfactant with alcohol as a material used for delivering drugs. In the case of the drug delivery, some drugs are encapsulated with a surfactant in order to be effectively transported in vivo; however, the surfactant accumulates in the body, which can cause various side effects, such as heart disease. Therefore, using new materials like alcohol for drug delivery will contribute to preventing the side effects caused by the surfactant.
“The surfactant is used for delivering drugs, but it is difficult to be expelled from the body. This will cause various side effects, such as heart diseases in asthmatic patients,” said Professor Kim. “I hope that using new materials, like alcohol, will free people from these side effects.”
(Marangoni-driven convection flow generated at the interface between water and alcohol, and the flow visualization results)
- A drop of alcohol on a water surface
- Comparison of mixing structures on the surface
- Marangoni mixing flow under the free surface
2017.08.18 View 7402 -
Professor Dan Keun Sung Endows Scholarship in Honor of His Retirement
Professor Dan Keun Sung in the School of Electrical Engineering contributed a 100 million KRW scholarship fund this month to KAIST to mark his retirement after more than three decades of work.
“As my retirement date comes closer, I have been thinking about what I could do for the school. I wanted to leave something behind, even though it’s small, for my lifelong school and students. I am hoping that this scholarship fund will benefit the members of KAIST.”
This isn’t his first time making a donation to KAIST. In 2013, Professor Sung donated ten million KRW, which was his cash prize from the 9th Haedong Academic Award of The Korean Institute of Communications and Information Sciences (KICS). At that time, Professor Sung had the chance to create a scholarship fund in his name; however, he wanted to highlight that the scholarship fund was for ‘someone,’ not created by ‘someone.’ In that sense, his scholarship fund was created with no name to benefit students in the School of Electrical Engineering. His colleagues and students supported his idea. Professor Seonghwan Cho, students, and alumni also participated in fund raising efforts, which reached 55 million KRW in total.
Professor Sung emphasized, “Donations should always be remembered, no matter how small they are.” He then explained his purpose for creating the scholarship fund by saying, “Fundraising can be truly meaningful to contributors, knowing that their money is going to supporting the school and students.”
Professor Sung, a fellow of the Institute of Electrical and Electronics Engineers (IEEE) Communication Society, started his post at KAIST in 1986. For the past 30 years, he has devoted himself to fostering young scholars and studying in the area of information and communication. He also participated in developing technologies for the resource management of various future cellular components, such as satellites, switchboards, and signaling networks.
2017.08.11 View 7915 -
Material-Independent Nanocoating Antimicrobial Spray Significantly Extends the Shelf Life of Produce
The edible coating on produce has drawn a great deal of attention in the food and agricultural industry. It could not only prolong postharvest shelf life of produce against external changes in the environment but also provide additional nutrients to be useful for human health. However, most versions of the coating have had intrinsic limitations in their practical application. First, highly specific interactions between coating materials and target surfaces are required for a stable and durable coating. Even further, the coating of bulk substrates, such as fruits, is time consuming or is not achievable in the conventional solution-based coating. In this respect, material-independent and rapid coating strategies are highly demanded.
The research team led by Professor Insung Choi of the Department of Chemistry developed a sprayable nanocoating technique using plant-derived polyphenol that can be applied to any surface. This new nanocoating process can be completed in seconds to form nanometer-thick films, allowing for the coating of commodity goods, such as shoe insoles and fruits, in a controlled fashion. For example, spray-coated mandarin oranges and strawberries show significantly-prolonged postharvest shelf life, suggesting the practical potential in edible coatings of perishable produce.
The technology has been patented and is currently being commercialized for widespread use as a means of preserving produce. The research results have recently been published in Scientific Reports on Aug 1.
Polyphenols, a metabolite of photosynthesis, possess several hydroxyl groups and are found in a large number of plants showing excellent antioxidant properties. They have been widely used as a nontoxic food additive and are known to exhibit antibacterial, as well as potential anti-carcinogenic capabilities. Polyphenols can also be used with iron ions, which are naturally found in the body, to form an adhesive complex, which has been used in leather tanning, ink, etc.
The research team combined these chemical properties of polyphenol-iron complexes with spray techniques to develop their nanocoating technology. Compared to conventional immersion coating methods, which dip substrates in specialized coating solutions, this spray technique can coat the select areas more quickly. The spray also prevents cross contamination, which is a big concern for immersion methods. The research team has showcased the spray’s ability to coat a variety of different materials, including metals, plastics, glass, as well as textile fabrics. The polyphenol complex has been used to form antifogging films on corrective lenses, as well as antifungal treatments for shoe soles, demonstrating the versatility of their technique.
Furthermore, the spray has been used to coat produce with a naturally antibacterial, edible film. The coatings significantly improved the shelf life of tangerines and strawberries, preserving freshness beyond 28 days and 58 hours, respectively. (Uncoated fruit decomposed and became moldy under the same conditions). See the image below.
a –I, II: Uncoated and coated tangerines incubated for 14 and 28 days in daily-life settings
b –I: Uncoated and coated strawberries incubated for 58 hours in daily-life settings
b –II: Statistical investigation of the resulting edibility.
Professor Choi said, “Nanocoating technologies are still in their infancy, but they have untapped potential for exciting applications. As we have shown, nanocoatings can be easily adapted for several different uses, and the creative combination of existing nanomaterials and coating methods can synergize to unlock this potential.”
2017.08.10 View 8634 -
Multi-Device Mobile Platform for App Functionality Sharing
Case 1. Mr. Kim, an employee, logged on to his SNS account using a tablet PC at the airport while traveling overseas. However, a malicious virus was installed on the tablet PC and some photos posted on his SNS were deleted by someone else.
Case 2. Mr. and Mrs. Brown are busy contacting credit card and game companies, because his son, who likes games, purchased a million dollars worth of game items using his smartphone.
Case 3. Mr. Park, who enjoys games, bought a sensor-based racing game through his tablet PC. However, he could not enjoy the racing game on his tablet because it was not comfortable to tilt the device for game control.
The above cases are some of the various problems that can arise in modern society where diverse smart devices, including smartphones, exist. Recently, new technology has been developed to easily solve these problems. Professor Insik Shin from the School of Computing has developed ‘Mobile Plus,’ which is a mobile platform that can share the functionalities of applications between smart devices.
This is a novel technology that allows applications to easily share their functionalities without needing any modifications. Smartphone users often use Facebook to log in to another SNS account like Instagram, or use a gallery app to post some photos on their SNS. These examples are possible, because the applications share their login and photo management functionalities.
The functionality sharing enables users to utilize smartphones in various and convenient ways and allows app developers to easily create applications. However, current mobile platforms such as Android or iOS only support functionality sharing within a single mobile device. It is burdensome for both developers and users to share functionalities across devices because developers would need to create more complex applications and users would need to install the applications on each device.
To address this problem, Professor Shin’s research team developed platform technology to support functionality sharing between devices. The main concept is using virtualization to give the illusion that the applications running on separate devices are on a single device. They succeeded in this virtualization by extending a RPC (Remote Procedure Call) scheme to multi-device environments.
This virtualization technology enables the existing applications to share their functionalities without needing any modifications, regardless of the type of applications. So users can now use them without additional purchases or updates. Mobile Plus can support hardware functionalities like cameras, microphones, and GPS as well as application functionalities such as logins, payments, and photo sharing. Its greatest advantage is its wide range of possible applications.
Professor Shin said, "Mobile Plus is expected to have great synergy with smart home and smart car technologies. It can provide novel user experiences (UXs) so that users can easily utilize various applications of smart home/vehicle infotainment systems by using a smartphone as their hub."
This research was published at ACM MobiSys, an international conference on mobile computing that was hosted in the United States on June 21.
Figure1. Users can securely log on to SNS accounts by using their personal devices
Figure 2. Parents can control impulse shopping of their children.
Figure 3. Users can enjoy games more and more by using the smartphone as a controller.
2017.08.09 View 8722 -
Students from Science Academies Shed a Light on KAIST
Recent KAIST statistics show that graduates from science academies distinguish themselves not only by their academic performance at KAIST but also in various professional careers after graduation.
Every year, approximately 20% of newly-enrolled students of KAIST are from science academies. In the case of the class of 2017, 170 students from science academies accounted for 22% of the newly-enrolled students. Moreover, they are forming a top-tier student group on campus. As shown in the table below, the ratio of students graduating early for either enrolling in graduate programs or landing a job indicates their excellent performance at KAIST.
There are eight science academies in Korea: Korea Science Academy of KAIST located in Busan, Seoul Science High School, Gyeonggi Science High School, Gwangju Science High School, Daejeon Science High School, Sejong Academy of Science and Arts, and Incheon Arts and Sciences Academy.
Recently, KAIST analyzed 532 university graduates from the class of 2012. It was found that 23 out of 63 graduates with the alma mater of science academies finished their degree early; as a result, the early graduation ratio of the class of 2012 stood at 36.5%. This percentage was significantly higher than that of students from other high schools.
Among the notable graduates, there was a student who made headlines with donation of 30 million KRW to KAIST. His donation was the largest donation from an enrolled student on record. His story goes back when Android smartphones were about to be distributed. Seung-Gyu Oh, then a student in the School of Electrical Engineering felt that existing subway apps were inconvenient, so he invented his own subway app that navigated the nearest subway lines in 2015. His app hit the market and ranked second in the subway app category. It had approximately five million users, which led to it generating advertising revenue. After the successful launch of the app, Oh accepted the takeover offered by Daum Kakao. He then donated 30 million KRW to his alma mater. “Since high school, I’ve always been thinking that I have received many benefits from my country and felt heavily responsible for it,” the alumnus of Korea Science of Academy and KAIST said. “I decided to make a donation to my alma mater, KAIST because I wanted to return what I had received from my country.” After graduation, Oh is now working for the web firm, Daum Kakao.
In May 24, 2017, the 41st International Collegiate Programming Contest, hosted by Association for Computing Machinery (ACM) and sponsored by IBM, was held in Rapid City, South Dakota in the US. It is a prestigious contest that has been held annually since 1977. College students from around the world participate in this contest; and in 2017, a total of 50,000 students from 2,900 universities in 104 countries participated in regional competitions, and approximately 400 students made it to the final round, entering into a fierce competition. KAIST students also participated in this contest. The team was comprised of Ji-Hoon Ko, Jong-Won Lee, and Han-Pil Kang from the School of Computing. They are also alumni of Gyeonggi Science High School. They received the ‘First Problem Solver’ award and a bronze medal which came with a 3,000 USD cash prize.
Sung-Jin Oh, who also graduated from Korea Science Academy of KAIST, is a research professor at the Korea Institute of Advanced Study (KIAS). He is the youngest recipient of the ‘Young Scientist Award’, which he received by proving a hypothesis from Einstein’s Theory of General Relativity mathematically at the age of 27. After graduating from KAIST, Oh earned his master’s and doctorate degrees from Princeton University, completed his post-doctoral fellow at UC Berkeley, and is now immersing himself in research at KIAS.
Heui-Kwang Noh from the Department of Chemistry and Kang-Min Ahn from the School of Computing, who were selected to receive the presidential scholarship for science in 2014, both graduated from Gyeonggi Science High School. Noh was recognized for his outstanding academic capacity and was also chosen for the ‘GE Foundation Scholar-Leaders Program’ in 2015. The ‘GE Foundation Scholar-Leaders Program’, established in 1992 by the GE Foundation, aims at fostering talented students. This program is for post-secondary students who have both creativity and leadership. It selects five outstanding students and provides 3 million KRW per annum for a maximum of three years.
The grantees of this program have become influential people in various fields, including professors, executives, staff members of national/international firms, and researchers. And they are making a huge contribution to the development of engineering and science. Noh continues doing various activities, including the completion of his internship at ‘Harvard-MIT Biomedical Optics’ and the publication of a paper (3rd author) for the ACS Omega of American Chemical Society (ACS).
Ahn, a member of the Young Engineers Honor Society (YEHS) of the National Academy of Engineering of Korea, had an interest in startup businesses. In 2015, he founded DataStorm, a firm specializing in developing data solution, and merged with a cloud back-office, Jobis & Villains, in 2016. Ahn is continuing his business activities and this year he founded, and is successfully running, cocKorea.
“KAIST students whose alma mater are science academies form a top-tier group on campus and produce excellent performance,” said Associate Vice President for Admissions, Hayong Shin. “KAIST is making every effort to assist these students so that they can perform to the best of their ability.”
(Clockwise from top left: Seung-Gyu Oh, Sung-Jin Oh, Heui-Kwang Noh and Kang-Min Ahn)
2017.08.09 View 7956 -
KAIST Researchers Receive Awards at the 13th Asian Congress on Biotechnology
(From left: Seon Young Park, Dr. So Young Choi, and Yoojin Choi)
Researchers in the laboratory of KAIST Distinguished Professor Sang Yup Lee from the Department of Chemical and Biomolecular Engineering swept awards at the 13th Asian Congress on Biotechnology held in Thailand last month. The conference awarded a total of eight prizes in the areas of best research and best poster presentation. This is an exceptional case in which members of one research team received almost half of the awards at an international conference.
Dr. So Young Choi received the Best Research Award, while Ph.D. candidates Yoojin Choi and Seon Young Park each received the Best Poster Presentation Award at the conference held in Khon Kaen, Thailand from July 23 to 27.
The Asian Congress on Biotechnology is an international conference in which scientists and industry experts in Asia and from around the world gather to present recent research findings in the field of biotechnology. At the conference, around 400 researchers in biotechnology from 25 countries, including Korea, gathered to present and discuss various research findings under the theme of “Bioinnovation and Bioeconomy.”
Distinguished Professor Sang Yup Lee attended the conference to give the opening plenary lecture on the topic of ‘Systems Strategies in Biotechnology.’ Professor Lee announced, “I have attended international conferences with students for the last 20 years, but this is the first in which my team received three awards at an international conference that only honors a total of eight awards, three for Best Research and five for Best Presentation.”
Dr. Choi presented research results on poly (lactate-co-glycolate) (PLGA) synthesis through a biological method using micro-organisms and received the Best Research Award. PLGA is a random copolymer of DL-lactic and glycolic acids and is a biopolymer widely used for biomedical applications. PLGA is biodegradable, biocompatible, and nontoxic, and thus has been approved by the US Food and Drug Administration (FDA) for its use in implants, drug delivery, and sutures.
Dr. Choi’s research was deemed to be innovative for synthesizing PLGA from glucose and xylose in cells through metabolic engineering of E.Coli. Dr. Choi received her Ph.D. under the supervision of Distinguished Professor Lee this February and is currently conducting post-doc research.
Ph.D. candidate Choi presented her research on the use of recombinant E.Coli for the biological synthesis of various nanoparticles and received the Best Poster Presentation award. Choi used recombinant E.Coli-expressing proteins and peptides that adsorb to heavy metals to biologically synthesize diverse metal nanoparticles such as single-nanoparticle including gold and silver, quantum dots, and magnetic nanoparticles for the first time. The synthesized nanoparticles can be used in the fields of bio-imaging, diagnosis, environment, and energy.
Ph.D. candidate Park, who also received the Best Poster Presentation award, synthesized and increased production of astanxanthin, a strong antioxidant found in nature, in E.Coli using metabolic engineering. Astanxanthin is a carotenoid pigment found in salmon and shrimp that widely used in health products and cosmetics.
2017.08.01 View 12735 -
Analysis of Gas Adsorption Properties for Amorphous Porous Materials
Professor Jihan Kim from the Department of Chemical and Biomolecular Engineering at KAIST has developed a method to predict gas adsorption properties of amorphous porous materials.
Metal-organic frameworks (MOFs) have large surface area and high density of pores, making them appropriate for various energy and environmental-related applications. And although most MOFs are crystalline, these structures can deform during synthesis and/or industrial processes, leading to loss in long-range order. Unfortunately, without the structural information, existing computer simulation techniques cannot be used to model these materials.
In this research, Professor Kim’s research team demonstrated that one can replace the material properties of structurally deformed MOFs with those of crystalline MOFs to indirectly analyze/model the material properties of amorphous materials. First, the team conducted simulations on methane gas adsorption properties for over 12,000 crystalline MOFs to obtain a large training set data, and created a resulting structure-property map. Upon mapping the experimental data of amorphous MOFs onto the structure-property map, results showed that regardless of crystallinity, the gas adsorption properties of MOFs showed congruence and consistency amongst one another.
Based on these findings, selected crystalline MOFs with the most similar gas adsorption properties as the collapsed structure from the 12,000 candidates. Then, the team verified that the adsorption properties of these similar MOFs can be successfully transferred to the deformed MOFs across different temperatures and even to different gas molecules (e.g. hydrogen), demonstrating transferability of properties.
These findings allow material property prediction in porous materials such as MOFs without structural information, and the techniques here can be used to better predict and understand optimal materials for various applications including, carbon dioxide capture, gas storage and separations.
This research was conducted in collaboration with Professor Dae-Woon Lim at Kyoto University, Professor Myunghyun Paik at Seoul National University, Professor Minyoung Yoon at Gachon University, and Aadesh Harale at Saudi Arabian Oil Company. The research was published in the Proceedings of the National Academy of Sciences (PNAS) online on 10 July and the co-first authors were Ph. D. candidate WooSeok Jeong and Professor Dae-Woon Lim.
This research was funded by the Saudi Aramco-KAIST CO2 Management Center.
(Figure 1. Trends in structure - material property map and in collapsed structures)
(Figure 2. Transferability between the experimental results of collapsed MOFs and the simulation results of crystalline MOFs)
2017.07.26 View 8520 -
Innovative Nanosensor for Disease Diagnosis
(Figure 1. Sensing Device)
(Figure 2. Protein templating route)
Breath pattern recognition is a futuristic diagnostic platform. Simple characterizing target gas concentrations of human exhaled breath will lead to diagnose of the disease as well as physical condition.
A research group under Prof. Il-Doo Kim in the Department of Materials Science has developed diagnostic sensors using protein-encapsulated nanocatalysts, which can diagnose certain diseases by analyzing human exhaled breath. This technology enables early monitoring of various diseases through pattern recognition of biomarker gases related to diseases in human exhalation.
The protein-templated catalyst synthesis route is very simple and versatile for producing not only a single component of catalytic nanoparticles, but also diverse heterogeneous intermetallic catalysts with sizes less than 3 nm. The research team has developed ever more sensitive and selective chemiresistive sensors that can potentially diagnose specific diseases by analyzing exhaled breath gases.
The results of this study, which were contributed by Dr. Sang-Joon Kim and Dr. Seon-Jin Choi as first authors were selected as the cover-featured article in the July issue of 'Accounts of Chemical Research,' an international journal of the American Chemical Society.
In human breath, diverse components are found including water vapor, hydrogen, acetone, toluene, ammonia, hydrogen sulfide, and carbon monoxide, which are more excessively exhaled from patients. Some of these components are closely related to diseases such as asthma, lung cancer, type 1 diabetes mellitus, and halitosis.
Breath analysis for disease diagnosis started from capturing exhaled breaths in a Tedlar bag and subsequently the captured breath gases were injected into a miniaturized sensor system, similar to an alcohol detector. It is possible to analyze exhaled breath very rapidly with a simple analyzing process. The breath analysis can detect trace changes in exhaled breath components, which contribute to early diagnosis of diseases.
However, technological advances are needed to accurately analyze gases in the breath, which occur at very low levels, from 1 ppb to 1 ppm. In particular, it has been a critical challenge for chemiresistive type chemical sensors to selectively detect specific biomarkers in thousands of interfering gases including humid vapor.
Conventionally, noble metallic catalysts such as platinum and palladium have been functionalized onto metal oxide sensing layers. However, the gas sensitivity was not enough to detect ppb-levels of biomarker species in exhaled breath.
To overcome the current limitations, the research team utilized nanoscale protein (apoferritin) in animals as sacrificial templates. The protein templates possess hollow nanocages at the core site and various alloy catalytic nanoparticles can be encapsulated inside the protein nanocages.
The protein nanocages are advantageous because a nearly unlimited number of material compositions in the periodic table can be assembled for the synthesis of heterogeneous catalytic nanoparticles. In addition, intermetallic nanocatalysts with a controlled atomic ratio of two different elements can be achieved using the protein nanocages, which is an innovative strategy for finding new types of catalysts. For example, highly efficient platinum-based catalysts can be synthesized, such as platinum-palladium (PtPd), platinum-nickel (PtNi), platinum-ruthenium (PtRu), and platinum-yttrium (PtY).
The research team developed outstanding sensing layers consisting of metal oxide nanofibers functionalized by the heterogeneous catalysts with large and highly-porous surface areas, which are especially optimized for selective detection of specific biomarkers. The biomarker sensing performance was improved approximately 3~4-fold as compared to the conventional single component of platinum and palladium catalysts-loaded nanofiber sensors. In particular, 100-fold resistance transitions toward acetone (1 ppm) and hydrogen sulfide (1 ppm) were observed in exhaled breath sensors using the heterogeneous nanocatalysts, which is the best performance ever reported in literature.
The research team developed a disease diagnosis platform that recognizes individual breathing patterns by using a multiple sensor array system with diverse sensing layers and heterogeneous catalysts, so that the people can easily identify health abnormalities. Using a 16-sensor array system, physical conditions can be continuously monitored by analyzing concentration changes of biomarkers in exhaled breath gases.
Prof. Kim said, “New types of heterogeneous nanocatalysts were synthesized using protein templates with sizes around 2 nm and functionalized on various metal oxide nanofiber sensing layers. The established sensing libraries can detect biomarker species with high sensitivity and selectivity.” He added, “the new and innovative breath gas analysis platform will be very helpful for reducing medical expenditures and continuous monitoring of physical conditions”
Patents related to this technology were licensed to two companies in March and June this year.
2017.07.19 View 9920