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2018-01 31 Headline News

[Academics][Researcher of the Month] Producing Energy by Wearing Clothes

Clothes that create electricity is not something in a movie anymore. In the midst of searching for various renewable energy, Professor Hong Jin-pyo (Department of Physics) created a new energy source that is created through friction in a single thread, as demonstrated in his research, ‘Hierarchically Nanostructured 1D Conductive Bundle Yarn-Based Triboelectric Nanogenerators.’ Hong conducted his research on energy-producing threads. When designing a wearable device, people generally think of light and slim devices attached on one’s clothes or body, usually charged by a solar heat system. This is referred as a two-dimension technology, as an object is placed upon another object. This does have its own benefits but also contains deficits such as weight and energy sources. Therefore, Hong created a one-dimension energy source – a thread that is used when weaving clothes. “Once a material is attached to clothing, the efficiency lacks uniformity,” explained Hong. He invented a thread that can produce energy itself, without having to attach anything onto a particular piece of clothing. The threads that make up the clothing could create energy itself. This thread, also named as a ‘triboelectric nanogenerator’, is a structure made from the notion of friction that we experience in our daily lives. For example, when we rub a balloon to our hair, friction occurs, resulting in a form of spiky hair. This phenomenon occurs when an electron is moved from one object to another, when these two objects continuously collide with each other. Depending on the characteristics of an object, one object would lose electrons and the other would gain electrons, meaning some sort of slight energy is formed. In this thread, polymer and aluminum are used; the former collects the electrons and the latter releases the electrons. Therefore, once the body wearing the clothing weaved from this thread moves, energy is created. The microscophic strucuture of a thread. (Photo courtesy of Hong) This triboelectric nanogenerator is still in the midst of its research. As this thread is extremely thin, Hong’s research team created a conductive bundle yarn so that they could have more strength. Moreover, he attached polymer-like nanostructures onto a single thread, so that the thread could have an increased surface area of energy production. Once energy is created through a larger surface area, bigger energy could be created within a single thread. This whole process is also known as a tribo electric effect. This one-dimension thread has a bright future in front of them, as technology closer to human are fondly being conducted on. “Once a sensor could be attached onto the thread, even more tasks could be done. This sensor could send whatever information they require to the owner’s smartphone, once the sensor adapts a Bluetooth function,” commented Hong, when asked about the future of this invention. He wished that this function would be able to let citizens to have control of their IoT (Internet of Things, a system of interrelated computing devices, mechanical and digital machines, object, animals or people that are provided with unique identifiers) through their energy producing clothes. "Keep trying! No matter what!" As Hong has not majored in clothing and textiles, he is not yet an expert of clothing, but has not been afraid of pioneering this area. “I had been proceeding my research in semiconductors at first. As new technologies evolved, I believed it was important to keep up with these changes to improve what I have been initially doing,” reminisced Hong. As he had achieved an unexpected success through his passion, he also gave the same advice to all Hanyangians. “Don’t make excuses. What really matters is whether you tried your best or not. I wish all of you can improve yourself through endless challenges!” On Jung-yun jessica0818@hanyang.ac.kr Photos by Choi Min-ju and Lee Jin-myung

2018-01 21

[Academics]Combination of Machinery and Medication

Diseases such as myocardial infarction, which are related to the blockage of blood vessels, are threatful diseases to both the suffering patients and the doctors who cure them. As vessels require great sensitivity and attention in the process of treatment, professor Jang Gun-hee (Department of Mechanical Engineering) proposed an alternative way in his article: ‘Magnetic Helical Robot for Targeted Drug-Delivery in Tubular Environments.' Jang has been working on this robot for 9 years. “Once one’s blood vessel is blocked, doctors have to use a thin tube made of medical grade materials, called a catheter,” Jang started off. With the catheter, doctors have to push it through the vessel to find the blocked area, inject a liquid for dissolution, then drill it out. This process itself is indeed difficult as they mostly have to depend on a doctor's experience and skills. However, doctors face another difficulty, with their own health affected during the procedure. "Doctors have to face countless radiation when curing a patient, since they have to keep track of the position of the catheter though x-rays. The doctors even wear clothes made of lead to obstruct the radiation, but still is not enough,” explained Jang. In order to solve this dangerous progress, Jang’s research team created a micro robot. This micro robot is made to swim within a vessel of seven to eight millimeters, to transport and emit the designated drug to the intended spot to dissolute the clot, and to drill itself on the clot, just as the catheter would do. This micro robot is moved by the magnetic field created outside of the body, allowing the doctors to be less exposed to radiation. Jang commented, “Once this method is in commercialization, doctors would be able to remote control the robots outside of the operating room, while having better controls within the surgery.” A picture describing the structure of a micro robot (Photo courtesy of Jang) From the midst of the interview, Jang explained the motivation of his research. “My mother’s coronary artery had been blocked 10 years ago and, doctors, therefore, had to insert a few catheters in her body. As this is a genetic phenomenon, I gave attention to the process and then realized the difficulties of these surgeries,’ reminisced Jang. Studies on magnetic robots have been ongoing since the past, especially in Switzerland and Germany. However, their research was mostly concentrated on the swimming itself, while Jang’s research team had to make the robot in command of various movements, which had to go through various trials and errors. Jang and his students are standing beside the machine they have made by themselves. Jang’s research team had to import pure iron from China, produce the frame in another factory, and transport this four-ton-machinery to school in order to materialize the machine required to magnetically steer the micro robot. Students had to coil the iron by hand, assemble the pieces together, to complete building this two-meter machine. Jang emphasized the importance of the activeness of Hanyangians through this example. “I continuously tell my students ‘no one can achieve anything if we can’t’. I hope students make a higher goal and achieve their dreams even if it takes a long time because they all have the capability do to so.” On Jung-yun jessica0818@hanyang.ac.kr Photos by Kang Cho-hyun

2017-11 20

[Academics]Conducting on a Sturdy Building

The current society is suffering from various natural and man-made disasters starting from terrors to earthquakes, such as the recent earthquake that panicked the citizens in Pohang. When a strong impact is made upon the ground, buildings require enough solidity to endure damage in order to protect the people. For a stronger, safer building, professor Yoo Doo-yeol (Department of Architectural Engineering) introduced an improvised concrete in his paper, ‘Effect of fiber geometric property on rate dependent flexural behavior of ultra-high-performance cementitious composite’. Yoo wishes to make sturdy structures for the citizens' safety. Most buildings are made of concrete, and it takes a huge part on the safety of a building. Concrete is initially vulnerable in tension, so there are already improvised versions of concrete commonly used in North America. The new model contains Micro steel fibers within the concrete to prevent the concrete from breaking into two big pieces. Through the steel fiber, the concrete only results in having micro-cracks even when a sudden weight is stressed upon the concrete. In this already improvised concrete, Yoo made a further research to strengthen this concrete in both quasi-static (a state in which something is almost still, but not completely) and impacted states. A ‘quasi-static’ state refers to an ordinary state with only mere impacts such as the vibration of footsteps everyday. These two states require a different sturdiness for different purposes, and the researchers concentrate on improving both of these conditions. Yoo focused on the aspect ratio of the micro steel fibers installed in the current improvised concrete. Aspect ratio is a numerical figure of the division of the diameter from the length of the fiber. Once this aspect ratio was changed in a quasi-static state, Yoo found out that the solidity was maintained and the energy absorption force was strengthened even when the amount of micro steel fibers were reduced. With the same amount of micro steel fibers with the changed ratio, Yoo was able to discover that the energy absorption force almost doubled within a shocked state. The results made through different aspect ratios. Micro-cracks can be seen within the pictures. (Photo courtesy of Yoo) Yoo emphasized the importance of this improvised matter. “Protecting the citizens within the buildings is becoming an urgent matter as countless accidents are occurring more frequently. The current structures lack enough safety to minimize the loss of lives.” The breaking of cement is distinctly more critical than the cracks in cement. Therefore, thorough research is required to make a sturdy building. “We had difficulties in capturing the process when the cement was impacted,” reminisced Yoo. The test cement is fully demolished within 0.001 second (a millisecond), and he had to capture all of the procedures within that millisecond. No kinetic equipment is available in Korea. As a result, he had to proceed with his research research by using the equipment from the University of British Columbia. Despite their mechanical hardships, Yoo made an innovative result in the field of architecture. 2017 is only his second year as a professor in Hanyang University. As the field of architecture is conservative, his final goal is to make practical application with his research. “Various factors such as durability and energy absorption force need to be considered when building a structure as it is directly related to the people living inside the building. This is only the beginning. I still have a lot more factors to work on, but I will continue my research enthusiastically until my studies can be applied to daily structures,” commented Yoo. Yoo will continue on with his goal to make a practical application with his discovery. On Jung-yun jessica0818@hanyang.ac.kr Photos by Choi Min-ju

2017-10 02

[Academics][Researcher of the Month] Producing Energy Through a Single Thread

'Lack of energy’ is an issue the whole world is focusing on. Various countries are searching for effective renewable energy and new materials that could replace the current energy sources. Professor Kim Seon-jeong (Department of Biomedical Engineering) discovered a new material every researcher was looking for. Kim's paper, “Harvesting electrical energy from carbon nanotube yarn twist” introduces the world’s first new material, which can produce energy through slight movements. Kim explains the concept of his new material Professor Kim’s research team started its first project in 2006 on artificial muscle. However, after his research, Kim realized its limitations as they were only able to move through an external energy source. Therefore, he thought of a new idea that the muscle would be more effective when it is able to produce energy by itself. Carbon nanotube is a new material which is a type of conductor and has a diameter of only a few nanometers. This material was made as a thread in the artificial muscle. However, when these threads were finely twisted into one direction, they were able to produce energy by itself through its contraction and relaxation without an applied voltage. Being made into a spring, their length can be changed as much as 30 percent on average. This new material, named as ‘twistron harvester yarn’, allowed a chance for the muscle to move by itself without a separate power source. This twistron harvester yarn looks and acts as if it were an ordinary thread. This states that making clothes out of this material is possible. Once this comes into realization, this would give a boost in making wearable devices, as producing electricity without an energy source is possible. Moreover, this thread is possible to use inside water, giving another possibility of an effective alternative energy. This has already been tested in the East Sea of Korea. Kim’s research team made a model consisting of a glass bottle connected with an electrode, the thread, a balloon, and an equipment that could measure electricity. As the twistron harvester yarn contracted and relaxed, electrical energy was verified from the ocean. Kim showed great passion in the research he was conducting. This research on the twistron harvester yarn was his fourth research. He has been working on artificial muscles for the past nine years before he started this research. “I didn’t start this research solely to find the twistron harvester yarn. I felt the limitations within the research I conducted earlier and was seeking for development,” reminisced Kim. He explained that he wasn’t the only person who conducted the research. Eight teams from three different countries worked on this new material for two years to deduct a better result. “We had a meeting through Skype every week, along with frequent visits to each team. Everyone had great passion and interest towards this research, and I believe that shows the firmness of this research,” said Kim. "Reach towards your own interest!" Kim also emphasized the attitudes Hanyangians should have towards their life. Even though he mainly teaches graduate school students, he wished all students could find what they truly wish to do. “Find something unique of your own. Find something you enjoy, and then you will be able to continue on with whatever you are doing. There are countless routes for all students. I wish students would keep challenging themselves to make the greatest results of their own,” wished Kim. Just as his words, Kim will continue with his work with great passion, for even better convenience for global citizens. On Jung-yun jessica0818@hanyang.ac.kr Photos by Kim Youn-soo

2017-09 11

[Academics]Making a Better Environment to Live In

Until the 21st century, the world has gone through excessive amounts of civilization. People were able to make various visible developments while failing to keep the environment without pollution. Professor Kim Ki-hyun of the Department of Civil and Environmental Engineering, therefore, focused on the environmental problems through his paper, “Biochar as a Catalyst”. Through the paper, he introduced a new material that could better purify various impurities. Biochar is a compound word of ‘bio’ and ‘char’, which is biology and charcoal. This material is a type of waste that is produced when you burn any biological materials that possess carbon. Just as charcoal is made when you burn trees, biochar is made when you burn biological materials. Through this not-so-helpful looking waste, people can purify the environment. When soil is polluted with something, such as oil, pesticides or heavy metal, biochar can be effectively used to absorb these contaminations. They combine well with toxic substances; therefore, it allows purification of soil only though scattering these materials in the soil and skimming them out again. The picture of the process of making biochar. (Photo courtesy of Kim) Kim introduced his overall research related to biochar. He studies various metal organic frameworks, which are much like biochars, used to purify polluted environments. “There are over 20 thousand types of metal organic frameworks, and I am currently working on which framework will be the most effective when purifying pollution,” explained Kim. Moreover, he talked about electronic cigarettes which are a relatively newly introduced invention. As there isn’t a proven result of the components within the electronic cigarette, Kim is working on the methods to discover the dangers of them. Kim said, “There isn’t a precise database related to electronic cigarettes. They could also consist of numerous cancer-causing agents and harm, just as original cigarettes does. I intend on discovering these substances and, furthermore, purify them.” Kim, however, does not solely research on this one material. He pays attention to the general issues within the society. His main interest lies on various aerial issues such as air pollution, fine dust, indoor pollution and stenches. Kim said, “There, indeed, are a lot of problems regarding pollution related issues. However, there are also a lot of methods that can be used to solve these problems. My goal is to make effective solutions through comprehensive research.” He explained that the biochar mentioned in his paper is only a small example of his overall goal. He intends to research on more new materials and solve various social issues. Kim hopes people could have correct information on the environment. Kim hopes that people would have a better understanding of environmental pollution. “When the dust level exceeds 100 microgram per 1 cubic meter, the Ministry of Environment suggests to refrain from going out. However, when people wear masks right after they smoke to protect themselves from fine dust, they breathe in eight hundred to nine hundred micrograms of dust. Due to excessive amounts of information, people sometimes make contradictory actions,” explained Kim. He wished that more environmental education would be made in the pursuit of proper knowledge. He added that Hanyang University students should give more interest towards the environment. “Let’s keep the air clean, with correct information!” On Jung-yun jessica0818@hanyang.ac.kr Photos by Park Young-min

2017-07 23

[Academics]Vitalization in Detecting NO2 in Daily Life

As environmental pollution is deteriorating, various hazardous gas face people unrecognizably in their daily lives. Professor Kim Hyoun-woo of the Division of Material Science and Engineering is an active researcher in various sensors that could help identify various gas, humidity, or even radiation. His recent paper “Enhancement of gas sensing properties by the functionalization of ZnO-branched SnO2 nanowires with Cr2O3 nanoparticles” proposes another effective method of detecting a particular gas, NO2. Kim expaining the nanostructure of his paper. His research aimed for an effective NO2 detecting nanostructure, which is a structure made from molecules. NO2, also called as nitrogen dioxide, is required to be detected since it can be found relatively easily through the atmosphere even when it is a toxic, air-contaminant gas. Kim mentioned “Once a practical method through this nanostructure is constructed, I wish people can be easily detect this toxic gas.” This nanostructure is composed of three different substances. First of all, a SnO2 (tin oxide) nanowire is required. A nanowire is a nanostructure of an extreme, fine line which has a diameter of one nanometer (10−9 meters). Next, ZnO (zinc oxide) nanowires are branched on the SnO2 nanowire. Then the last substance, which are Cr2O3 (chromium oxide) nanoparticles, would grow on the ZnO nanowires. With a completed nanostructure, detecting NO2 become possible. An illustration of Cr2O3 -functionalized ZnO branched SnO2 nanowires. (photo courtesy of Kim) This nanostructure mentioned in his paper is highly sensitive, which makes it a significant structure. A current always flows within a structure, and a resistance is made whenever there is a current. However, the resistance differs when there is an inflow of another gas. The external gas takes away the electron in the structure, therefore heightening the resistance of the structure. The sensitivity is determined through resistance within the sensor. When the sensitivity is elevated, a structure can perceive more NO2 than the one with low sensitivity even when there’s a same amount in the air. The nanostructure mentioned in the paper is indeed a unique technology. However, Kim also mentioned the insufficiency of this nanostructure. In order to detect NO2, this gas needs to be heated in an extremely high temperature; in the case of the paper, 300’C. Therefore, there is a difficulty for people to sense the gas in the current stance. Kim mentioned that he wants to improve this difficulty through further research. He is currently working on methods that could allow this nanostructure to detect NO2 in a room temperature. Kim wishes to develop a practical nanostructure. Kim is an enthusiastic researcher. He constantly works on structures that could benefit people in their daily lives. He is striving for extreme-high sensitivity in his structures so that people could quickly recognize and react to the contamination. Kim mentioned “I want to make a structure that can be commercialized. A lot of the inventions disappear due to the lack of cost competency or efficiency. I wish to contribute to the promotion of mankind welfare.” On Jung-yun jessica0818@hanyang.ac.kr Photos by Kim Youn-soo