Engineering
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Hanmaeum Education Corps Invites Multicultural Families
About 100 graduates from the Multicultural Mother Schools and their families visited the KAIST campus on October 29 at the invitation of the Hanmaeum Education Corps of KAIST. The Hanmanum Education Corps is a volunteering organization composed of KAIST faculty and students. Many retired KAIST faculties are also members of the corps. Byong Kyu Choi, an Emeritus Professor from the Department of Industrial and Systems Engineering, is the director of the corps and has been leading the event since 2015.
With the support of a KAIST educational volunteering organization called SEED(Social Education Embracing Diversity), this year’s event offered various activities including a treasure hunt and convergent science programs. Participants had the opportunity to experience KAIST’s educational environment and enjoyed the perfect autumn weather during outdoor activities with student volunteers.
Children enjoyed making illumination-music stickers with the KAIST students, even though it was tough to learn at first.
While the children engaged themselves in the science program, parents visited the chrysanthemum fair and some of KAIST’s cafeterias.
Hanmaeum Education Corps opened the Multicultural Mother Schools to support multicultural mothers so that they can have more interest in and help their children more with their education. Since its establishment in 2015, the Multicultural Mother Schools have been expanding throughout the country.
The corporation hopes that visiting a renowned university will encourage children from multicultural families to study hard in addition to offering self-enrichment opportunities through career exploration and science activities.
2017.10.30 View 5248 -
Distinguished Professor Lee Named International Fellow of the CAS
Distinguished Professor Sang Yup Lee from the Department of Chemical and Biomolecular Engineering at KAIST was awarded the title of distinguished professor and international fellow from the Chinese Academy of Sciences (CAS), and honorary professor from its affiliated organization the Tianjin Institute of Industrial Biotechnology (TIB).
The CAS recognized Distinguished Professor Lee for his significant contributions to biotechnology. He has made significant pioneering academic achievements in the area of systems metabolic engineering, which produces useful chemicals from microorganisms. Not only did he develop the first and best source technology in that field, but also came out with processes for the production of biofuel and environmentally-friendly chemicals.”
As a global leader in systems metabolic engineering, Distinguished Professor Lee has also been appointed as an honorary professor at Jiangnan University in Wuxi, China.
Distinguished Professor Lee was listed in the ‘Top 20 Translational Researchers of 2014’ selected by the renowned international journal Nature Biotechnology. Moreover, he was the first Asian recipient of the James E. Bailey Award in 2016 and Marvin J. Johnson Award in 2012, which are given to scholars in the field of biotechnology.
He is also one of 13 global scientists who are foreign members of the renowned academic societies the National Academy of Engineering and the National Academy of Sciences in the US. Furthermore, he received the ‘2017 Korea Best Scientist Award’ from the president of Korea in July. Finally, his founding field, systems metabolic engineering, was chosen as one of the ‘Top 10 Emerging Technologies of 2016’ by the World Economic Forum.
The Chinese Academy of Sciences, established in November 1949, is an academic organization that carries out research on basic sciences and natural sciences in China. It defined its science and technology system to include the fields of basic sciences, natural sciences, and high technology. While having a base in Beijing, its branch academies are located in 12 main cities along with 117 affiliates and 100 national key labs.
2017.10.26 View 11777 -
Development of a Highly-Accurate Computational Model of Human Metabolism
A research team from KAIST developed a computational framework that enables the reconstruction of a comprehensive computational model of human metabolism, which allows for an accurate prediction of personal metabolic features (or phenotypes).
Understanding personal metabolic phenotypes allows us to design effective therapeutic strategies for various chronic and infectious diseases. A human computational model called the genome-scale metabolic model (GEM) contains information on thousands of metabolic genes and their corresponding reactions and metabolites, and has played an important role in predicting metabolic phenotypes. Although several versions of human GEMs have been released, they had room for further development, especially as to incorporating biological information coming from a human genetics mechanism called “alternative splicing.” Alternative splicing is a genetic mechanism that allows a gene to give rise to multiple reactions, and is strongly associated with pathology.
To tackle this problem, Jae Yong Ryu (a Ph.D. student), Dr. Hyun Uk Kim (Research Fellow), and Distinguished Professor Sang Yup Lee, all from the Department of Chemical and Biomolecular Engineering at KAIST, developed a computational framework that systematically generates metabolic reactions, and adds them to the human GEM. The resulting human GEM was demonstrated to accurately predict metabolic phenotypes under varied environmental conditions. The research results were published online in Proceedings of the National Academy of Sciences (PNAS) on October 24, 2017, under the title “Framework and resource for more than 11,000 gene-transcript-protein-reaction associations in human metabolism.”
The research team first updated the biological contents of a previous version of the human GEM. The updated biological contents include metabolic genes and their corresponding metabolites and reactions. In particular, metabolic reactions catalyzed by already-known protein isoforms were additionally incorporated into the human GEM; protein isoforms are multiple variants of proteins generated from individual genes through the alternative splicing process. Each protein isoform is often responsible for the operation of a metabolic reaction. Although multiple protein isoforms generated from one gene can play different functions by having different sets of protein domains and/or subcellular localizations, such information was not properly considered in previous versions of human GEMs.
Upon the initial update of the human GEM, named Recon 2M.1, the research team subsequently implemented a computational framework that systematically generates information on Gene-Transcript-Protein-Reaction Associations (GeTPRA) in order to identify protein isoforms that were previously not identified. This framework was developed in this study. As a result of the implementation of the framework for GeTPRA, more than 11,000 GeTPRA were automatically predicted, and thoroughly validated. Additional metabolic reactions were then added to Recon 2M.1 based on the predicted GeTPRA for the previously uncharacterized protein isoforms; Recon 2M.1 was renamed Recon 2M.2 from this upgrade.
Finally, Recon 2M.2 was integrated with 446 sets of personal biological data (RNA-Seq data) in order to build patient-specific cancer models. These patient-specific cancer models were used to predict cancer metabolism activities and anticancer targets.
The development of a new version of human GEMs along with the computational framework for GeTPRA is expected to boost studies in fundamental human genetics and medicine. Model files of the human GEMs Recon 2M.1 and 2M.2, a full list of the GeTPRA and the source code for the computational framework to predict the GeTPRA are all available as part of the publication of this study.
Distinguished Professor Lee said, “The predicted GeTPRA from the computational framework is expected to serve as a guideline for future experiments on human genetics and biochemistry, whereas the resulting Recon 2M.2 can be used to predict drug targets for various human diseases.”
This work was supported by the Technology Development Program to Solve Climate Changes on Systems Metabolic Engineering for Biorefineries (NRF-2012M1A2A2026556 and NRF-2012M1A2A2026557) from the Ministry of Science and ICT through the National Research Foundation (NRF) of Korea.
(Figure 1:A scheme of Recon 2M.1 development and its use in reconstructing personal genome-scale metabolic models (GEMs). (A) A concept of alternative splicing of human genes and its use in Gene-Transcript-Protein-Reaction Associations (GeTPRA) of Recon 2M.1. (B) A procedure of systematic refinement of the Recon 2Q. Recon 2Q is one of the previously released human GEMs. Biochemically inconsistent reactions include unbalanced, artificial, blocked, and/or redundant reactions. Iterative manual curation was conducted while validating the Recon 2M.1. (C) Reconstruction of cancer patient-specific GEMs using Recon 2M.1 for further simulation studies. In this study, personal biological data (RNA-Seq data) were obtained from The Cancer Genome Atlas (TCGA; https://cancergenome.nih.gov/ ) across the ten cancer types.
(Figure 2: Computational framework for the systematic generation of Gene-Transcript-Protein-Reaction Associations (GeTPRA; red box in the flowchart). Peptide sequences of metabolic genes defined in Recon 2M.1 were retrieved from a database called Ensembl. EC numbers and subcellular localizations of all the protein isoforms of metabolic genes in Recon 2M.1 were predicted using software programs EFICAz2.5 and Wolf PSort, respectively. Information on the newly predicted GeTPRA was systematically incorporated into the Recon 2M.1, thereby resulting in Recon 2M.2.)
2017.10.25 View 10171 -
Professor Dai Gil Lee Recognized by the ICCS
Emeritus Professor Dai Gil Lee, from the School of Mechanical and Aerospace Engineering at KAIST, received a special achievement award from the 20th International Conference on Composite Structures (ICCS).
ICCS is a renowned conference in the field of applied composite structures, which highlights the practicality of composite structures. This year, the conference was held at the Conservatoire National des Arts et Métiers (CNAM), Paris, France from September 4 to 7. Approximately 650 papers were presented from 45 countries.
Especially, the conference honored Emeritus Professor Lee, who has been engaged in ICCS since 1993 and received best paper award twice. The ICCS recognized him for serving with distinction in science and technology in the fields of composite materials and structures. As a member of the Editorial Board for many years, he gave significant support to the journal Composite Structures. At the conference, he gave a special lecture titled ‘Lightweight Carbon Composite Proton Exchange Membrane Fuel Cells’.
Professor Lee said, “I will dedicate myself to innovate Vanadium Redox Flow Battery-ESS (VRFB) based on the research findings announced at the conference and related patents. I am hoping that these efforts will contribute to solving energy issues around the world.”
2017.10.19 View 8198 -
Ultra-Fast and Ultra-Sensitive Hydrogen Sensor
(From left: Professor Kim, Ph.D. candidate Koo, and Professor Penner)
A KAIST team made an ultra-fast hydrogen sensor that can detect hydrogen gas levels under 1% in less than seven seconds. The sensor also can detect hundreds of parts per million levels of hydrogen gas within 60 seconds at room temperature.
A research group under Professor Il-Doo Kim in the Department of Materials Science and Engineering at KAIST, in collaboration with Professor Reginald M. Penner of the University of California-Irvine, has developed an ultra-fast hydrogen gas detection system based on a palladium (Pd) nanowire array coated with a metal-organic framework (MOF).
Hydrogen has been regarded as an eco-friendly next-generation energy source. However, it is a flammable gas that can explode even with a small spark. For safety, the lower explosion limit for hydrogen gas is 4 vol% so sensors should be able to detect the colorless and odorless hydrogen molecule quickly. The importance of sensors capable of rapidly detecting colorless and odorless hydrogen gas has been emphasized in recent guidelines issued by the U.S. Department of Energy. According to the guidelines, hydrogen sensors should detect 1 vol% of hydrogen in air in less than 60 seconds for adequate response and recovery times.
To overcome the limitations of Pd-based hydrogen sensors, the research team introduced a MOF layer on top of a Pd nanowire array. Lithographically patterned Pd nanowires were simply overcoated with a Zn-based zeolite imidazole framework (ZIF-8) layer composed of Zn ions and organic ligands. ZIF-8 film is easily coated on Pd nanowires by simple dipping (for 2–6 hours) in a methanol solution including Zn (NO3)2·6H2O and 2-methylimidazole.
(This cover image depicts lithographically-patterned Pd nanowires overcoated with a Zn-based zeolite imidazole framework (ZIF-8) layer.)
As synthesized ZIF-8 is a highly porous material composed of a number of micro-pores of 0.34 nm and 1.16 nm, hydrogen gas with a kinetic diameter of 0.289 nm can easily penetrate inside the ZIF-8 membrane, while large molecules (> 0.34 nm) are effectively screened by the MOF filter. Thus, the ZIF-8 filter on the Pd nanowires allows the predominant penetration of hydrogen molecules, leading to the acceleration of Pd-based H2 sensors with a 20-fold faster recovery and response speed compared to pristine Pd nanowires at room temperature.
Professor Kim expects that the ultra-fast hydrogen sensor can be useful for the prevention of explosion accidents caused by the leakage of hydrogen gas. In addition, he expects that other harmful gases in the air can be accurately detected through effective nano-filtration by using of a variety of MOF layers.
This study was carried out by Ph.D. candidate Won-Tae Koo (first author), Professor Kim (co-corresponding author), and Professor Penner (co-corresponding author). The study has been published in the online edition of ACS Nano, as the cover-featured image for the September issue.
Figure 1. Representative image for this paper published in ACS Nano, August, 18.
Figure 2. Images of Pd nanowire array-based hydrogen sensors, scanning electron microscopy image of a Pd nanowire covered by a metal-organic framework layer, and the hydrogen sensing properties of the sensors.
Figure 3. Schematic illustration of a metal-organic framework (MOF). The MOF, consisting of metal ions and organic ligands, is a highly porous material with an ultrahigh surface area. The various structures of MOFs can be synthesized depending on the kinds of metal ions and organic ligands.
2017.09.28 View 11070 -
Sangeun Oh Recognized as a 2017 Google Fellow
Sangeun Oh, a Ph.D. candidate in the School of Computing was selected as a Google PhD Fellow in 2017. He is one of 47 awardees of the Google PhD Fellowship in the world.
The Google PhD Fellowship awards students showing outstanding performance in the field of computer science and related research. Since being established in 2009, the program has provided various benefits, including scholarships worth $10,000 USD and one-to-one research discussion with mentors from Google.
His research work on a mobile system that allows interactions among various kinds of smart devices was recognized in the field of mobile computing. He developed a mobile platform that allows smart devices to share diverse functions, including logins, payments, and sensors. This technology provides numerous user experiences that existing mobile platforms could not offer. Through cross-device functionality sharing, users can utilize multiple smart devices in a more convenient manner. The research was presented at The Annual International Conference on Mobile Systems, Applications, and Services (MobiSys) of the Association for Computing Machinery in July, 2017.
Oh said, “I would like to express my gratitude to my advisor, the professors in the School of Computing, and my lab colleagues. I will devote myself to carrying out more research in order to contribute to society.”
His advisor, Insik Shin, a professor in the School of Computing said, “Being recognized as a Google PhD Fellow is an honor to both the student as well as KAIST. I strongly anticipate and believe that Oh will make the next step by carrying out good quality research.”
2017.09.27 View 12335 -
Draining Eyes Clogged with Glaucoma
Professor Gou Young Koh in the Graduate School of Medical Science and Engineering and his team have identified a new mechanism involved in the development and progression of glaucoma, and found a potential therapeutic option to treat it. Glaucoma is the second cause of irreversible blindness, after cataracts. It affects about 3.5% of the world population aged 40 to 80.
Professor Koh also serves as the director of the Center for Vascular Research at the Institute for Basic Science. The IBS said the study, published in the Journal of Clinical Investigation, is expected to help the development of therapies to treat primary open-angle glaucoma (POAG), which counts for three quarters of all glaucoma patients.
One of the most important risk factors for glaucoma is the increased pressure inside the eye. A liquid called aqueous humor is constantly produced and drained out from the eye. It transports nutrients and inflates the eye giving it a roughly spherical shape. However, if this fluid cannot flow out of the eye chambers freely, an increase in intraocular pressure can damage the optic nerve, leading to vision loss. The precise mechanism of elevated resistance to aqueous humor outflow remains unclear, and although the current treatments for glaucoma tackle the production and outflow of aqueous humor, their outcomes are still poor.
A component of the eye that plays a fundamental role in draining out the aqueous humor is Schlemm's canal. It collects the aqueous humor and mediates its transfer from the eye chambers to blood circulation. The cells on the walls of the canal, endothelial cells, ship the liquid from the inner to the outer side in “packages”, called vacuoles. As the shape and number of the vacuoles reflects the outflow performance, several giant vacuoles are expected in the normal outflow process.
The team explained how imbalances in Schlemm's canal significantly increase the risk of glaucoma. They showed that an important regulator for canal functionality is the angiopoietin-Tie2 system. Angiopoietins, such as Ang1 and Ang2, are proteins important for the growth of new blood vessels and Tie2 is the receptor that binds them. It is known that the angiopoietin-Tie2 system plays a role in Schlemm’s canal formation, as Tie2 mutations or angiopoietin absence result in congenital glaucoma. However, this study clarified that it is also critically important during adulthood.
The researchers reported that adult mice deficient in Tie2 suffer from an elevated intraocular pressure, retinal neuronal damage and partial visual impairment. Moreover, they had a markedly decreased number of giant vacuoles inside Schlemm’s canal endothelial cells, which indicate a poor aqueous humor drainage.
The scientists also investigated if and how this process changes in older mice, as aging is a major risk factor for glaucoma, and showed that aged mice experience reduced levels of giant vacuoles, Tie2, Ang1, and Ang2, as well as other proteins connected with the angiopoietin-Tie2 pathway, like Prox1.
To test whether Tie2 activation could shift the situation, the researchers tested the antibody ABTAA (Ang2-binding and Tie2-activating antibody). They injected it in one eye of mice, while the other eye of the same mice functioned as the negative control. After one week, levels of Tie2 and Prox1, number and diameter of giant vacuoles in Schlemm’s canals increased in the ABTAA-treated eyes compared to control eyes. The researchers observed a similar outcome with decreased intraocular pressure when ABTAA was injected to the eyes of mice suffering from POAG with regressed Schlemm’s canals, indicating that this antibody might be considered as a therapeutic option.
"Slow development of glaucoma treatments is partly due to the poor understanding of the underlying pathogenesis," said Professor Koh, the corresponding author of the study. "We hope that identifying the critical role of the angiopoietin-Tie2 system in adult Schlemm’s canals will bring a significant boost in the development of therapeutics."
Figure 1: Schlemm's canal position inside the eye.
Schlemm's canal (green) plays a fundamental role in draining the aqueous humor (white arrows) from the anterior chamber of the eye to blood circulation. If the aqueous humor is not able to flow out freely, elevated intraocular pressure damages the optical nerve causing glaucoma and eventually blindness.
Figure 2: Electron microscope images reveal how the aqueous humor is packaged in vacuoles (arrowheads) inside the cells forming the walls of Schlemm's canal.
Aging and glaucoma cause the number and size of giant vacuoles to decrease, meaning that the aqueous humor outflow is compromised. The images compare the giant vacuoles in Schlemm's canals of a healthy mouse (top) and a mouse lacking Tie2 (bottom)
Figure 3: The Ang2-binding and Tie2-activating antibody (ABTAA) rejuvenates the eye of aged mice and rescues them from glaucoma.
Aging causes a reduction of the protein Tie2, a risk factor for increased intraocular pressure and glaucoma. In this experiment, one eye of mice lacking Ang1 and Ang2 was injected with the premixed ABTAA and Ang2, while the other eye was used as negative control. The researchers observed an increase in the area of Schlemm’s canal, together with higher levels of Tie2 (red) and lower intraocular pressure, suggesting that ABTAA restores the canal's functionality. The image includes the transcription factor Prox1 (green) and CD144 (blue), a protein present at the junctions between cells that form the wall of the canal. The angiopoietin-Tie2 system and Prox1 are linked by a vicious circle: the less Tie2 and Ang2, the less Prox1, leading to Schlemm's canal damage, increase in intraocular pressure, and acceleration of glaucoma progression.
2017.09.19 View 7478 -
Semiconductor Patterning of Seven Nanometers Technology Using a Camera Flash
A research team led by Professor Sang Ouk Kim in the Department of Materials Science and Engineering at KAIST has developed semiconductor manufacturing technology using a camera flash.
This technology can manufacture ultra-fine patterns over a large area by irradiating a single flash with a seven-nanometer patterning technique for semiconductors. It can facilitate the manufacturing of highly efficient, integrated semiconductor devices in the future.
Technology for the Artificial Intelligence (AI), the Internet of Things (IoTs), and big data, which are the major keys for the fourth Industrial Revolution, require high-capacity, high-performance semiconductor devices. It is necessary to develop lithography technology to produce such next-generation, highly integrated semiconductor devices.
Although related industries have been using conventional photolithography for small patterns, this technique has limitations for forming a pattern of sub-10 nm patterns.
Molecular assembly patterning technology using polymers has been in the spotlight as the next generation technology to replace photolithography because it is inexpensive to produce and can easily form sub-10 nm patterns. However, since it generally takes a long time for heat treatment at high-temperature or toxic solvent vapor treatment, mass production is difficult and thus its commercialization has been limited.
The research team introduced a camera flash that instantly emits strong light to solve the issues of polymer molecular assembly patterning. Using a flash can possibly achieve a semiconductor patterning of seven nanometers within 15 milliseconds (1 millisecond = 1/1,000 second), which can generate a temperature of several hundred degrees Celsius in several tens of milliseconds.
The team has demonstrated that applying this technology to polymer molecular assembly allows a single flash of light to form molecular assembly patterns.
The team also identified its compatibility with polymer flexible substrates, which are impossible to process at high temperatures. Through these findings, the technology can be applied to the fabrication of next-generation, flexible semiconductors.
The researchers said the camera flash photo-thermal process will be introduced into molecular assembly technology and this highly-efficiency technology can accelerate the realization of molecular assembly semiconductor technology.
Professor Kim, who led the research, said, “Despite its potential, molecular assembly semiconductor technology has remained a big challenge in improving process efficiency.” “This technology will be a breakthrough for the practical use of molecular assembly-based semiconductors.”
The paper was published in the international journal, Advanced Materials on August 21 with first authors, researcher Hyeong Min Jin and PhD candidate Dae Yong Park.
The research, sponsored by the Ministry of Science and ICT, was co-led Professor by Keon Jae Lee in the Department of Materials Science and Engineering at KAIST, and Professor Kwang Ho Kim in the School of Materials Science and Engineering at Pusan National University.
(1. Formation of semiconductor patterns using a camera flash)
(Schematic diagram of molecular assembly pattern using a camera flash)
(Self-assembled patterns)
2017.09.18 View 11517 -
Professor Jun Ho Oh's Total Solar Eclipse Featured in the APOD, NASA
(Professor Jun Ho Oh)
A video of a total solar eclipse, filmed in Warm Springs, Oregon by Professor Jun Ho Oh of the Department of Mechanical Engineering, was selected as the Astronomy Picture of the Day (APOD).
APOD, is a NASA website specializing in astronomy pictures. It features astronomical observations recorded by the Hubble Space Telescope or photos taken by astronomical observers from around the world.
Professor Oh is now the second Korean and the first amateur photographer whose photo was selected as the APOD.
According to the website, ‘the video frames were acquired with equipment specifically designed by Jun Ho Oh to track a close-up of the Sun’s periphery during the eclipse.’
Also, Digital Photography Review (dpreview.com) introduced observation points of the eclipse in his three-minute video, including solar prominences, corona, and Baily’s beads.
Professor Oh, the creator of the bipedal walking humanoid robot named Hubo, has been chasing eclipse since his first trip to Turkey in 1999.
“After numerous trials and failures over the last 18 years, I was finally able to capture every single breath-taking moment of the total eclipse,” said the professor.
He’s already planning for the next total eclipse in Chile on July 2, 2019.
Click the link to watch the video https://apod.nasa.gov/apod/ap170912.html
(#1 Photo of solar eclipse)
(#2 Photo of solar eclipse)
2017.09.14 View 6994 -
Professor Jin Woo Kim Wins the 14th Macrogen Scientist Award
Professor Jin Woo Kim of the Department of Biological Sciences at KAIST received the 14th Macrogen Scientist Award at the 2017 KSMCB International Conference held in COEX on September 12, 2017.
The award is given by the Korean Society for Molecular and Cellular Biology (KSMCB) and sponsored by Macrogen, a service provider of genome research. The award was established in 2004 to recognize biological scientists who have accomplished excellent performance in the field of basic life sciences.
Professor Kim has achieved outstanding research performances on nerve development, such as identifying the cause of senile retinal degenerative disease and finding retinal nerve cells that distinguish light and darkness in dark conditions.
Recently, he discovered intercellular communication, which controls the development of retinal neurons. His findings have contributed to addressing the principles of maintenance and regeneration of retinal neurons.
Since joining KAIST, he has presented approximately 20 papers and published in numerous international journals including Cell Reports, Genes and Development, and EMBO Journal. Moreover, he delivered special lectures at international conferences, universities, and institutes around the world.
2017.09.14 View 9145 -
Humicotta Wins the Silver Prize at the 2017 IDEA
The 3D-printed ceramic humidifier made by the research team led by Professor Sang-Min Bae won the silver prize at the 2017 International Design Excellence Awards (IDEA). Professor Bae’s ID+IM team was also listed as winners of three more appropriate technology designs at the IDEA. The awards, sponsored by the Industrial Designers Society of America, are one of the three prestigious design awards including the Red Dot Design Award and the iF Design Award in Germany.
The silver prize winner in the category of home and bath, Humicotta is an energy-efficient, bacteria free, and easy to clean humidifier. It includes a base module and filter. The base is a cylindrical pedestal with a built-in fan on which the filter is placed. The filter is a 3D-printed honeycomb structure made of diatomite. When water is added, the honeycomb structure and porous terracotta maximize natural humidification. It also offers an open platform service that customizes the filters or provides files that users can use their own 3D printer.
Professor Bae’s team has worked on philanthropy design using appropriate technology as their main topic for years. Their designs have been recognized at prestigious global design awards events, winning more than 50 prizes with innovative designs made for addressing various global and social problems.
The Light Funnel is a novel type of lighting device designed for off-grid areas of Africa. It helps to maximize the natural light effect in the daytime without any drastic home renovations. It consists of a transparent acrylic sphere and a reflective pathway. After filling the acrylic sphere with water and placing it on a rooftop, sunlight passes into the house through the water inside the sphere. It provides a lighted environment nine times brighter than without it. Also, once installed, it can be used almost permanently.
The Maasai Smart Cane is made using wood sticks purchased through fair trade with the Maasai tribe. GPS is installed into the grip of the birch-tree cane, so that cane users can send a signal when in an emergency situation. All of the proceeds of this product go to the tribe.
S.Cone is a first aid kit made in collaboration with Samsung Fire and Marine Insurance. The traffic cone-shaped kit is designed to help users handle an emergency situation intact and safe. The S.Cone has unique versions for fires, car accidents, and marine accidents. For example, the S.Cone for fires is equipped with a small fire extinguisher, smoke mask, and fire blanket. The cap of the S.Cone also functions as an IoT station connecting the fire and gas detector with smart phones.
Professor Bae said of his team’s winning design products, “By making the data public, any person can design their own humidifier if they have access to a 3D-printer. We want it to be a very accessible product for the public. The Light Funnel and Maasai Smart Cane are designed for economically-marginalized populations and the elderly. We will continue to make the best designed products serving the marginalized 90% of the population around the world.”
2017.09.14 View 26691 -
A Novel and Practical Fab-route for Superomniphobic Liquid-free Surfaces
(clockwise from left: Jaeho Choi, Hee Tak Kim, Shin-Hyun Kim)
A joint research team led by Professor Hee Tak Kim and Shin-Hyun Kim in the Department of Chemical and Biomolecular Engineering at KAIST developed a fabrication technology that can inexpensively produce surfaces capable of repelling liquids, including water and oil.
The team used the photofluidization of azobenzene molecule-containing polymers to generate a superomniphobic surface which can be applied for developing stain-free fabrics, non-biofouling medical tubing, and corrosion-free surfaces.
Mushroom-shaped surface textures, also called doubly re-entrant structures, are known to be the most effective surface structure that enhances resistance against liquid invasion, thereby exhibiting superior superomniphobic property.
However, the existing procedures for their fabrication are highly delicate, time-consuming, and costly. Moreover, the materials required for the fabrication are restricted to an inflexible and expensive silicon wafer, which limits the practical use of the surface.
To overcome such limitations, the research team used a different approach to fabricate the re-entrant structures called localized photofludization by using the peculiar optical phenomenon of azobenzene molecule-containing polymers (referred to as azopolymers). It is a phenomenon where an azopolymer becomes fluidized under irradiation, and the fluidization takes place locally within the thin surface layer of the azopolymer.
With this novel approach, the team facilitated the localized photofluidization in the top surface layer of azopolymer cylindrical posts, successfully reconfiguring the cylindrical posts to doubly re-entrant geometry while the fluidized thin top surface of an azopolymer is flowing down.
The structure developed by the team exhibits a superior superomniphobic property even for liquids infiltrating the surface immediately.
Moreover, the superomniphobic property can be maintained on a curved target surface because its surficial materials are based on high molecules.
Furthermore, the fabrication procedure of the structure is highly reproducible and scalable, providing a practical route to creating robust omniphobic surfaces.
Professor Hee Tak Kim said, “Not only does the novel photo-fluidization technology in this study produce superior superomniphobic surfaces, but it also possesses many practical advantages in terms of fab-procedures and material flexibility; therefore, it could greatly contribute to real uses in diverse applications.”
Professor Shin-Hyun Kim added, “The designed doubly re-entrant geometry in this study was inspired by the skin structure of springtails, insects dwelling in soil that breathe through their skin. As I carried out this research, I once again realized that humans can learn from nature to create new engineering designs.”
The paper (Jaeho Choi as a first author) was published in ACS Nano, an international journal for Nano-technology, in August.
(Schematic diagram of mushroom-shaped structure fabrication)
(SEM image of mushroom-shaped structure)
(Image of superomniphobic property of different types of liquid)
2017.09.08 View 7813