Department of Mechanical Engineering

Sang Hoon Kang, Professor in the Department of Mechanical Engineering at UNIST has been honored to receive the 2020 Hakbo Assistive Robotic Technology (ART) Award from the Korea Robotics Society (KROS). Established in 2013, the Hakbo ART Award is bestowed on young researchers, under the age of 45 years, who have demonstrated outstanding accomplishments in the area of robotics research. This award typically recognizes the significance of a particular contribution to the field of rehabilitation and health care robotics. Each year, one outstanding researcher is selected for the KROS Hakbo ART Award. This award has been presented to Professor Kang in recognition of his achievements and contributions to the development of the robotics industry in 202o. The award presentation ceremony took place during the KROS annual general meeting, held on December 4, 2020. This award is particularly special for us because it has been established through a generous donation from the late Professor Emeritus Zeungnam Bien, the father of Korean robotics, who passed away in 2017. The late Professor Emeritus Zeungnam Bien put his heart and soul into robotics research for the weak. Besides, he has contributed greatly to the area of human-friendly robotics for rehabilitation. Professor Sang Hoon Kang, a leading expert in the field rehabilitation robotics, has received considerable research attention in recent years for developing an intelligent robot for stroke rehabilitation, as well as the study on the gait analysis of patients with knee osteoarthritis. In recent years, he has embarked on research cooperation for the rehabilitation of people with special needs in Ulsan region, in partnership with Ulsan Metropolitan City 2nd Special Needs Gymnasium. In addition, through cooperation with the Ulsan Occupational Accident Public Hospital, which will open in 2024, Professor Kang and his research team aim to expand their research capacities in the field of wokplace accident rehabilitation.

On December 2, UNIST signed an industry-academic cooperation agreement with Hankuk Fiber Co., Ltd. In the memorandum of understanding, the two organizations promised to form a strategic partnership for the purpose of laying the groundwork for leading the future mobility era. This agreement has been made in an effort to seek mutual growth based on joint research and development, information sharing, and exchange of technology and human resources. To this end, the two organizations have pledged to work towards the development of cutting-edge molding technologies for composite materials through the use of UNIST's research manpower and infrastructure for high-speed molding of lightweight composite materials, combined with Hankuk Fiber Co., Ltd.'s production capabilities. Under this partnership, both organizations have also promised to strengthen their competitiveness in the existing defense, aviation, and automobile industries, in addition to solidifying industry-academia collaboration. Chief Director YoungGil Cho (right) and Dean Sung Youb Kim (College of Engineering, UNIST) are posing for a portrait at the MoU signing ceremony on December 2, 2020. Hankuk Fiber Co., Ltd., based in Miryang-si, Gyeongsangnam-do, is the nation's leading composite products manufacturer that produces resin and fiberglass products for the construction industry. Through its aerospace and defense division, based on its 50-year know-how and expertise in the development of composite bombproof helmets, the company has managed to be at the forefront of the global defense industry. Furthermore, its technology contributes to Korea's space development and receives credit from all over the world. Centering around the Composites Research Center (Director Young-Bin Park), UNIST has been carrying out various research on the high-speed molding of lightweight composite materials. The center is equipped with high-speed molding equipment for advanced composite materials, worth 10 billion won, and thus is staffed with research manpower, specialized in all areas of composite materials, such as molding, material, and analysis. Took place in the 6F main conference room, located in the Main Administration Building at UNIST, the ceremony has been attended by Dean Sung Youb Kim in the College of Engineering (UNIST), Head Young-Bin Park in the Department of Mechanical Engineering (UNIST), Professor Wooseok Ji (Department of Mechanical Engineering) from UNIST. Also Present at the signing ceremony were Chief Director YoungGil Cho and other key officials from the Defence and Aerospace Division of Hankuk Fiber Co., Ltd.

UNIST is spurring innovation to lead the future mobility era in Ulsan, the heart of Korea's automobile industry. On November 26, the UNIST Center for Smart Mobility, in collaboration with Ulsan city, has held the official inauguration ceremony for the participating companies' directors' council meeting, inviting over 30 small-and midium-sized enterprises (SMEs) and venture businesses in Ulsan region. The council plans to revitalize the future mobility-related industries through the operation of various support programs for SMEs and providing regularly scheduled technical exchange meetings, centered on the eight representative technology divisions. [embed]https://youtu.be/kgsd6c09yN8[/embed] In October 2020, UNIST showcased some of its breakthorugh research achievements at the 'Korean New Deal! Eco-friendly Future Mobility On-site Visit' event, which took place at Hyundai Motor's Ulsan plant. The event, which has been attended by President Moon Jae-in, as well as many distinguished business leaders, government officials, and academic leaders, consisted of the strategies to foster the future car market and various exhibitions, featuring the outstanding achievements of Hyundai Motor Company and UNIST. To this end, UNIST has showcased a total of 7 R&D achievements, thereby displaying the competitiveness of the future mobility. The first introduced was the Personal Air Vehicle (PAV) by Professor Hungsun Son (Department of Mechanical Engineering). At the event, Professor Son gave an explanation for the current research project, utilizing PAV Pilot Training Simulator, as well as the development status of vehicles, capable of vertical takeoff and landing. PAV by Professor Hungsun Son is being test-driven by Finance Minister Hong Nam-ki. l Image Credit: The Blue House's Facebook Page Following this, Professor Cheolhyeon Kwon (Department of Mechanical Engineering) introduced his ongoing research on ultra-compact self-driving EV, capable of delivering safe urban driving. Along with this, an autonomous vehicle, currently being tested on UNIST campus has been showcased at the event. Not only that, an ultra lightweight, high-rigidity 3D-printed electric vehicle by Professor Namhun Kim (Department of Mechanical Engineering) has attracted great attention. It was even test-driven by President Moon Jae-in. The Department of Design has also introduced some of their personal mobility research achievements, which includes 'AngGo' by Professor Hui Sung Lee and 'Oro Plume' by Professor Yunwoo Jeong. AngGo by Professor Hui Sung Lee (Department of Deign) is being test-driven. l Image Credit: The Blue House's Facebook Page During the course of the event, Professor Yunwoo Jeong also introduced his 911$ Rescue Drone that has been honored at the international design competition, iF Design Awards 2020. The key to this is that compared to the existing rescue process, it is easy to use and allows quick and safe evacuation and rescue. The main feature is to float 1m above air. The current research status of hyperloop, namely U-Loop by Professor Joo Hwan Oh (Department of Mechanical Engineering) has also been introduced. PAV Pilot Training Simulator l Image Credit: The Blue House's Facebook Page Meanwhile, UNIST has held the official signboard-hanging ceremony of its newly-established UNIST Center for Smart Mobility in May 2020 to accelerate their efforts to lay the groundwork for leading the future automotive industry. The center is in charge of various research in the field of future mobility, such as Design, Materials, Battery, Components/Modules, Automated Driving, Personal Air Vehicles (PAVs), System Integration, and Mobility-as -a-Service (MaaS).

On November 18, UNIST conducted an award ceremony to recognize the winners of its 2020 UNIST Department PR Video Contest. This contest has been carried out in an effort to enhance the competitiveness of each department at UNIST since the recent academic reorganization. From July to October 2020, a total of 6 video submissions have been received. Those departments that partook in the contest were the Department of Mechanical Engineering, the Department of Materials Science and Engineering, the Department of Urban and Environmental Engineering, the Department of Design, the Department of Biomedical Engineering, and the Department of Physics. The excellence award has been given to the Department of Mechanical Engineering, along with the KRW 3 million prize money. Each winning department has been presented with an award certificate in addition to prize money. The excellence award has been presented to the Department of Mechanical Engineering, along with a prize money of approximately KRW 3 million. The outstanding award has been given to the Department of Materials Science and Engineering, accompanied by a prize money of KRW 2 million. The encouragement award has been granted to the Department of Urban and Environment Engineering, along with a prize money of KRW 1 million. Other departments who participated in the contest have also been presented with the participation prize, accompanied by a prize money of approximately KRW 500,000. President Yong Hoon Lee presented these awards to the winning department representatives and shared a pleasant conversation with them. Department of Mechanical Engineering [embed]https://youtu.be/ltCLu6nE3s8[/embed] Department of Materials Science and Engineering [embed]https://youtu.be/mzHOiDgETz8[/embed] Department of Urban and Environmental Engineering [embed]https://youtu.be/t8IEatxN-CM[/embed] Department of Design [embed]https://youtu.be/yj8sehzCr4E[/embed] Department of Biomedical Engineering [embed]https://youtu.be/9NZOK5nXGWI[/embed] Department of Physics [embed]https://youtu.be/RxSYjHJVd24[/embed]

The School of Mechanical and Aerospace and Nuclear Engineering at UNIST has announced the appointment of two of its alumni as assistant professors at Yeungnam University and Wonkwang University, respectively. Both UNIST alumni, Hyun-Ha Park (Advisor: Professor Hoon-Eui Jeong) and Changyoon Jeong (Advisor: Professor Young-Bin Park) were recently awarded honorary doctorates from the 2020 UNIST's Virtual Commencement Ceremony, which took place on August 27, 2020. Dr. Park received her doctorate in Mechanical, Aerospace and Nuclear Engineering under the mentorship of Professor Hoon-Eui Jeong at UNIST. Her research interests lies primarily in the area of micro/nanoscale structures. In particular, she focused on manufacturing bio-inspired micro/nano structures with anti-fouling and anti-microbial properties. As a result, she not only succeeded in developing antifouling materials that suppress the adhesion of bacteria on their surfaces, but also creating moving antifouling surfaces that control surface movement. She will begin her term as an assistant professor in the Department of Mechanical Engineering at Wonkwang University on September 1, 2020. Dr. Jeong received his doctorate in Mechanical, Aerospace and Nuclear Engineering under the mentorship of Professor Young-Bin Park at UNIST. His research interests lies primarily in the area of lightweight multi-functional composite materials. From structural design to manufacturing, Dr. Jeong has been conducting research in various fields. He will begin his term as an assistant professor in the Department of Mechanical Engineering at Yeungnam University, beginning September 1, 2020. In addition to realizing an improvement in physical properties of the existing composite materials, Dr. Jeong aims to develop the next-generation of smart materials with higher utilization through research that could additionally implement energy-harvesting and sensing functions. The new composite materials with the implemented smart functions, such as self-diagnosis and treatment, are poised to transform the cars and robots of the future. Meanwhile, UNIST held a virtual celebration, honoring the Class of 2020 and celebrating their achievements in a manner that is safe and complies with national health protocols. At the ceremony, a total of 1,325 graduating students joined a family of over 4,500 UNIST alumni. The pre-recorded ceremony is now available on UNIST’s official youtube channel.

UNIST embarks on research cooperation for the rehabilitation of people with special needs in Ulsan region. The signing ceremony of the MoU among the System Design and Control Engineering (SDC, Director Namhum Kim) track of UNIST, the Robotics and Rehabilitation Engineering Laboratory (Professor Sang Hoon Kang) at UNIST, and the Ulsan Metropolitan City 2nd Special Needs Gymnasium took place on June 18, 2020. The main purpose of this agreement is to improve the health and community welfare systems for those with special needs in Ulsan region. Under this partnership, they have also agreed to strengthen cooperation in promoting and supporting research projects, involving △ Mutual cooperation projects to promote physical function recovery and improved health for the disabled △ Development of robot-assisted stroke rehabilitation programs. The research, being conducted at the Robotics and Rehabilitation Engineering Laboratory by Professor Sang Hoon Kang focuses on the robot design, robot motion/force control, and Biomechanics, system identification, signal processing and other relevant technologies for rehabilitation. Based on these studies, in 2017, he has made noteworthy innovations, such as developing a robotic device for assessments of muscle overactivity and movement dysfunction in stroke survivors. "We hope the rehabilitation robots developed through this partnership will help improve the quality of life of people with disabilities," says Professor Kang.

UNIST embarks on research cooperation for the rehabilitation of people with special needs in Ulsan region. The signing ceremony of the MoU among the System Design and Control Engineering (SDC, Director Namhum Kim) track of UNIST, the Robotics and Rehabilitation Engineering Laboratory (Professor Sang Hoon Kang) at UNIST, and the Ulsan Metropolitan City 2nd Special Needs Gymnasium took place on June 18, 2020. The main purpose of this agreement is to improve the health and community welfare systems for those with special needs in Ulsan region. Under this partnership, they have also agreed to strengthen cooperation in promoting and supporting research projects, involving △ Mutual cooperation projects to promote physical function recovery and improved health for the disabled △ Development of robot-assisted stroke rehabilitation programs. The research, being conducted at the Robotics and Rehabilitation Engineering Laboratory by Professor Sang Hoon Kang focuses on the robot design, robot motion/force control, and Biomechanics, system identification, signal processing and other relevant technologies for rehabilitation. Based on these studies, in 2017, he has made noteworthy innovations, such as developing a robotic device for assessments of muscle overactivity and movement dysfunction in stroke survivors. "We hope the rehabilitation robots developed through this partnership will help improve the quality of life of people with disabilities," says Professor Kang.

A technique to control the direction and rate of transport of colloidal particles in solution has been developed, using the partial concentration difference of salt occurs in salt water. As the operation required of them is very simple and no external power supply is necessary, it is expected to provide efficient environmental monitoring, such as pollutant field analysis in less developed countries. Professor Taesung Kim and his research team in the School of Mechanical Aerospace and Nuclear Engineering at UNIST presented a dynamic transport control mechanism for colloidal particles by developing a micro-/nanofluidic DP platform (MNDP). This device can be easily applied to select specific components from cells mixed with fine particles of various sizes, or to identify contaminant components, and to synthesize quantum dot materials used for semiconductors and select only the same size. have. The advantage is that it operates purely from forces that differ from electrolyte ion concentrations. The range of applications for controlling microparticles of various sizes ranging from nanometers (nm, 1 millionth of a meter) to micrometers (μm, one millionth of a million) is increasing. As a result, there have been many technologies for dealing with fine particles freely. Until now, it was difficult to apply them directly in the field because an external device such as a high-pressure environment or an electronic device was needed. Figure 1. Concept, fabrication, and working mechanism of the hybrid-scale micro-/nanofluidic DP platform (MNDP). (a) Schematic of the MNDP in the production of a stable concentration gradient in the target chamber through a nanochannel. (b) Microscopic images of the MNDP filled with 1 mM of fluorescence dye. In this study, the microfluidic device is a "diffusiophoresis" technology that controls the movement of charged microparticles by naturally regulating the forces generated by differences in electrolyte ions. In diffusiophoresis technology, microparticles are powered by osmotic pressure and electric field. Osmotic pressure always moves the fine particles in the solution from a low concentration of ions to a high one, but the direction of moving the fine particles by the electric field changes depending on the type of electrolyte used. For example, in the case of salt (NaCl), the diffusion rate of anion (Cl-) is fast, so that the place where the ion concentration is relatively low is the cathode, and the place where the concentration is high becomes the anode. Move to place (anode). On the other hand, when an electrolyte with a fast cation diffusion rate is used, the direction of the electric field is reversed, which causes the force to move the fine particles from the low ion concentration to the high (cathode). Figure 2. Simple and on-demand extraction of the preconcentrated colloidal particles. The team developed a microfluidic device that can effectively control these two forces created by the difference in electrolyte ion concentrations, using nanochannels with diameters that can only pass ions. If the osmotic pressure acting on the microparticles in the microfluidic device and the direction of the force due to the electric field are the same, the particles are concentrated. If the two forces are opposite, the concentrated microparticles are extracted by the electric force. Using this microfluidic device, the microparticles of 1 micrometer-sized negative charge inside the brine were successfully concentrated to 300 times the concentration for 1 hour. In addition, by changing the type of electrolyte and reversing the direction of the electric field, the concentrated microparticles could be extracted within 10 minutes. "Since the effect of the electric field and osmotic pressure varies depending on the size of the fine particles, it is possible not only to concentrate and extract one type of particle, but also to effectively separate fine particles of different sizes," says Dogyeong Ha in the PhD program of Mechanical Engineering at UNIST, the first author of the study. "Our study is significant academically in that it is the result of experimentally proved diffusion phenomena that finely regulates electrolyte ions to control the movement of microparticles," says Professor Kim. "This device is easy to manufacture and operate and requires no external power, so it can be applied to the diagnosis of environmental conditions directly in the harsh environment or in developing countries." The findings of this research have been published in ACS Nano on October 10, 2019. This study has been supported by the National Research Foundation of Korea (NRF) through the Korean government (MSIT). All microfabrication processes were performed at the UNIST Central Research Facility Center. Journal Reference Dogyeong Ha, Sangjin Seo, Kyunghun Lee, and Taesung Kim, "Dynamic Transport Control of Colloidal Particles by Repeatable Active Switching of Solute Gradients," ACS Nano, (2019).

Lightweight and durable composites are still the dominant materials in aerospace application. A team of researchers from UNIST has reported developing a new composite manufacturing technique, that is not only cheaper, but also simpler and more environmentally friendly. The team, led by Professor Young-Bin Park and Professor Wooseok Ji in the School of Mechanical Aerospace and Nuclear Engineering at UNIST, has been selected to lead a government-funded aerospace R&D project, together with Korea Aerospace Industries (KAI). This research project is part of the Development Project of Advanced Process Technologies for Aircraft Parts by the Ministry of Trade, Industry and Energy (MOTIE). The research team will receive up to KRW 10 billion in research funding over the five-year period, starting in July 2019. Under the topic of Development of 4 Meter or Longer Integrated Composite Skin·Stringer Module and 3 Meter or Longer Thermoplastic Composite Fuselage Module for Single Aisle Commercial Aircraft Based on the AFP and OOA Processes, the research team will carry out window frame production, using recycled thermoplastic composites. Through this, they will develop technologies to produce high-quality composite parts, while increasing resource efficiency in the existing composite manufacturing processes. The composite material currently used in the manufacture of aircraft structures are made from non-recyclable thermoset plastics. However, thermoplastic injection molding requires high heat and high pressure in order to successfully create parts. The equipment used in such process is known as, Autoclave. In general, larger autoclaves are expected for the production of large-scale aircraft components and such equipment is costly and often takes over 10 hours for the epoxy resin to be hardened. From left are Professor Wooseok Ji and Professor Young-Bin Park in the School of Mechanical Aerospace and Nuclear Engineering at UNIST. "There are limits to traditional composite molding processes, as thermoset plastics were never designed to be recyclable in the first place. Besides, larger autoclaves are quite poor at managing productivity," says Professor Ji. "Our research project aims to discard the existing manufacturing process and show innovative eco-friendly materials and enhanced productivity." Researchers have set out to develop a novel molding method that could produce parts in minutes using recycled thermoplastic composites. In particular, from basic technology to actual product development, this project is wide ranging. This project magnifies the role of UNIST in that it entails actual product production, rather than merely working on technology development. The success of joint projects, like this, where universities and businesses work together for the commercialization of outstanding technologies, was largely due to the Fraunhofer Project Center for Composites Research@UNIST (FPC@UNIST) at UNIST. The aerial view of Fraunhofer Project Center for Composites Research@UNIST (FPC@UNIST) at UNIST. Professor Young-Bin Park, who realized the importance of high-speed molding technology for composites early on, has made constant efforts in laying the groundwork for research and development of lightweight composite materials. This put in place the foundations for the successful launch of the new Korean branch of Fraunhofer research group in 2016. The center has secured a total of KRW 20 billion from the Korean Ministry of Trade, Industry and Energy and the Ulsan city over a period of four years. This new research center is about 1,634 square meters and boasts KRW 10 billion worth high-speed molding equipment for carbon fiber reinforced composites, currently being operated. "Development of new processes for recycling and remanufacturing composite materials is a crucial research topic being studied in laboratories," says Professor Park. "Through this project, we plan on developing technologies, capable of recycling of retired aircraft components into new parts, thus making it applicable to other industries where composite materials are used."

A new patterning technique based on the natural liquid foam systems, observed in soap, beer, and even embryogenesis, has been developed. Their findings provide a simple and low-cost patterning method for fabricating fine patterns on the substrates, used in semiconductors and flexible displays. In the study, Professor Taesung Kim and his research team in the School of Mechanical Aerospace and Nuclear Engineering at UNIST, presented a simple and versatile microfluidic approach for controlling two-dimensional liquid foam, designing not only evaporative microholes for directed drainage to generate desired film networks without topological changes for the first time, but also microposts to pin the generated films at set positions. Published in the August 2019 issue of Nature Communications, this will promotes the development of wearable devices that are difficult to manufacture with conventional electron beam lithography or photolithography methods. Electron beam lithography (often abbreviated as e-beam lithography or EBL) is the preferred patterning method for product development. However, this approach is time-consuming and has a low output yield, in addition to the costly associated equipment and materials. To overcome these drawbacks, various patterning approaches, using liquid foams are currently being studied. Yet, their use has been limited due to their dynamic fluidity, complex topological changes, and physical characteristics of the closed system. Professor Kim's team focused on the bubble structure commonly found in nature and created an unprecedented system through microfluidic devices. The liquid mixed with the necessary material on the substrate is naturally evaporated through a microfluidic device to easily create a regularly connected two-dimensional pattern. The natural foam is the "closed system," in which active physical access to manipulate foam is unavailable. Besides, as a result of bubble merging through Ostwald ripening, it has been difficult to obtained well-ordered nanostructure patterns. To address these issues, the research team devised a micro-/nanofluidic liquid-mediated patterning (MNLP) technique to innovate 2D liquid foam from the conventional closed system (i.e., closed-cell 2D liquid foam) into an unprecedented open system (i.e., open-cell 2D liquid foams). "To the best of our knowledge, we are the first to investigate the mechanism of open-cell 2D liquid foam and characterize the MNLP technique to shape various liquid film networks," says Juyeol Bae in the doctoral program of Mechanical Aerospace and Nuclear Engineering at UNIST, the first author of the study. "Patterning materials in liquid is achievable using the thin films as nanoscale molds, which has additional potential through repeatable patterning on a substrate and combination with a lithographic technique." "In contrast to traditional lithography, the new technique has the advantage of transferring large-scale patterns onto flexible substrates," says Professor Kim. "This technique provides novel means of nanofabrication superior to both lithographic and bottom-up state-of-the-art techniques." The findings of this study have been published online in the July 2019 issue of Nature Communications, a sister journal of Nature. This study has been supported by the National Research Foundation of Korea (NRF), funded by the Korean government (MSIT). Journal Reference Juyeol Bae et al., "Controlled open-cell two-dimensional liquid foam generation for micro- and nanoscale patterning of materials," Nature Communications, (2019).