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Exploring Psychological Similarities and Neurophysiological Differences in Internet Gaming and Alcohol Use Disorder
A collaborative research team led by Professor Jung-Seok Choi from the Department of Psychiatry at Samsung Medical Center, Sungkyunkwan University, and Professor Woo-Young Ahn from the Department of Psychology at Seoul National University has identified the shared and distinct psychological and neurophysiological characteristics of IGD and AUD using artificial intelligence techniques. This study was recently published in the Comprehensive Psychiatry, and the research was conducted by Ji-Yoon Lee (first author, Department of Healthcare and Convergence Science, Seoul National University) and Myeong Seop Song (co-first author, Department of Psychology, Seoul National University), among others. Substance use disorder typically involves the repeated use of substances that directly affect the body—most notably alcohol and drugs. In recent years, however, excessive engagement in certain behaviors such as gambling, gaming, and shopping has gained attention as another form of addiction, referred to as behavioral addiction. While the triggers may differ—substances versus behaviors—numerous studies have reported that substance use disorder and behavioral addiction share similarities in terms of clinical symptoms, disease progression, genetic underpinnings, and neural abnormalities. Based on these similarities, the 11th revision of the International Classification of Diseases (ICD-11) officially included "disorders due to addictive behaviors", and in 2018, both gambling disorder and gaming disorder were recognized as formal diagnoses by the World Health Organization. However, despite this recognition, the neurological basis of behavioral addictions remains insufficiently understood, and there is ongoing debate as to whether they should be considered brain disorders on par with substance addictions. This underscores the need to elucidate the neural mechanisms underlying behavioral addiction and determine how they overlap or diverge from those associated with substance addiction. In South Korea, one of the most prevalent behavioral addictions is IGD characterized by excessive and persistent use of online games. The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) includes IGD as a condition warranting further study. Previous research has indicated that individuals with IGD often exhibit psychological symptoms such as depression, anxiety, and impulsivity, similar to those with AUD. However, the specific neural mechanisms that distinguish or connect these two disorders have not been fully clarified. Therefore, the present study aimed to compare the neurophysiological and psychological characteristics of IGD and AUD using a multimodal machine learning framework, integrating both EEG data and neuropsychological features. We analyzed both the neurophysiological and psychological characteristics of IGD and AUD using artificial intelligence models applied to multimodal data—resting-state EEG signals recorded with eyes closed, and standardized psychological assessments. A total of 191 participants were included in the study: 67 individuals with IGD, 58 with AUD, and 66 healthy controls. From the EEG data, the researchers extracted both sensor-level (channel-based) and source-level (brain-region-based) connectivity features. In parallel, they collected psychological data, including measures of depression, anxiety, impulsivity, and intelligence quotient (IQ). Three machine learning algorithms were used for classification: L1-norm logistic regression, support vector machines, and random forest. We compared models trained using EEG data alone, psychological data alone, and a multimodal model that integrated both. Figure 1. Multimodal analysis framework The multimodal L1-norm logistic regression model achieved the highest performance in distinguishing IGD from AUD, with a classification accuracy of 71.2%—surpassing the models with neuropsychogical or EEG data. Notably, the results revealed that connectivity differences in delta and beta frequency bands—particularly within the right orbitofrontal cortex, prefrontal cortex, temporal lobe, and anterior cingulate cortex—played a key role in distinguishing the two disorders. These regions are associated with reward processing and cognitive control, suggesting distinct patterns of neural dysfunction between IGD and AUD. In contrast, psychological features such as depression, anxiety, and impulsivity did not significantly differ between the two groups, highlighting that while IGD and AUD may share similar psychological profiles and exhibit distinct neurophysiological patterns. Figure 2. Feature importance according to beta coefficients: comparison between IGD and AUD This study is the first to compare behavioral addiction and substance use disorder using both non-invasive and cost-effective EEG data and neuropsychological assessments. It offers a potential technical foundation for the early diagnosis, personalized treatment, and potential development of digital therapeutics for addiction-related disorders. Moreover, the multimodal machine learning approach achieved high classification performance and shows great potential for broader application in the diagnosis and prognosis of various psychiatric conditions.
- No. 304
- 2025-04-28
- 141
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Next-Gen Wearable Haptic Electronics for Immersive XR and Sensory Substitution
Professor Jaeyoung Yoo’s team, in collaboration with Professor John Rogers' group at Northwestern University, has developed a groundbreaking wireless, skin-attachable haptic interface that mimics the complexity of human touch. This research introduces the "Full Freedom-of-Motion (FOM) Actuator," a compact device capable of delivering multidirectional tactile stimuli—including pressure, vibration, stretching, sliding, and twisting—by precisely engaging various mechanoreceptors in the skin. Unlike conventional haptic technologies that primarily rely on unidirectional vibrations, the FOM actuator employs a nested configuration of electromagnetic coils and magnets to generate dynamic, programmable forces in all directions. This design enables the device to produce complex tactile sensations, offering a more realistic and immersive user experience in extended reality (XR) applications. The research team demonstrated the device's versatility through various applications. For instance, by attaching the haptic interface to different body parts such as the back of the hand, fingers, or arms, visually impaired users could receive navigation cues through tactile feedback, facilitating precise hand movements and object detection without visual input. Additionally, the device successfully replicated the textures of materials like fabric and metal, enhancing the realism of virtual object interactions. Notably, the team converted sound frequency information from musical instruments into distinct vibration patterns, allowing users to perceive musical components through touch alone, thereby offering a novel sensory substitution method for individuals with hearing impairments. The haptic platform is designed to be compact, lightweight, and capable of delivering high-resolution tactile feedback. It ensures a high data transmission rate per device and features wireless control via Bluetooth, along with a flexible material structure optimized for skin contact. These attributes make it a promising tool for various applications, including XR-based gaming, medical training, rehabilitation, and sensory assistive devices. Professor Jaeyoung Yoo remarked, “This research demonstrates the potential of advanced actuator technology capable of physically stimulating diverse tactile receptors. It offers promising applications not only as assistive technology for individuals with sensory impairments but also as a core interface for more immersive XR experiences.” The study, titled “Full freedom-of-motion actuators as advanced haptic interfaces,” was published in the March 28, 2025, issue of the journal Science. This international collaboration was supported by the National Research Foundation of Korea (Global Research Laboratory Program) and the Ministry of Trade, Industry and Energy (Core Technology Development for Robot Industry Program). ▲ Flexible haptic electronic system for omnidirectional tactile stimulation on skin ▲ Omnidirectional tactile stimulation technology utilizing a stimulation mechanism that takes into account human skin sensory receptors ▲ Auditory stimulation through omnidirectional tactile feedback (top), tactile navigation via object tracking in real-time smart glasses footage (bottom left), and texture reproduction in virtual reality environments (bottom right).
- No. 303
- 2025-04-23
- 330
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South Korea’s landmark ruling on climate justice
Professor Gilwon Lee of the Law School at Sungkyunkwan University and Professor Taejung Park of the Graduate School of Future Strategy at KAIST have become the first legal scholars from South Korea to publish in the Correspondence section of Nature Human Behaviour, a sister journal of the world-renowned journal Nature. Their article, published on April 8, analyzes a recent Constitutional Court ruling on climate justice in Korea from the perspective of international environmental law. In August 2023, Korea’s Constitutional Court ruled that a key provision in the government’s 2021 climate law was unconstitutional, on the grounds that it failed to adequately protect the lives and safety of citizens. This marked the first such ruling in Asia, setting a potentially influential precedent that reinforces the government's legal responsibility in responding to climate change. The case is particularly significant because it was initiated by young people. The court declared Article 8, Clause 1 of the Framework Act on Carbon Neutrality unconstitutional. This provision is central to setting national greenhouse gas reduction targets. The Court found that the article lacked specific targets for the years 2031–2049, thereby undermining consistency in climate policy. While the clause remains in effect until February 28, 2026, the Court sent a strong message that the National Assembly must revise the law. The Court based its decision on the principles of prohibition of insufficient protection and legality reservation. It stressed that the protection of fundamental rights must be substantial, and that national climate targets must be clearly defined by law, not left to executive discretion. The ruling also addressed the structural limitations of democracy, noting that future generations lack direct representation in today’s decision-making processes. Therefore, the legislature must legally enshrine long-term climate goals. Professors Lee and Park emphasized that this ruling carries significant global implications. They argued that it is not merely an environmental policy decision, but a constitutional precedent that reinforces intergenerational equity and democratic accountability. They underscored that effective climate action must focus on legally binding long-term goals, rather than short-term gains. The scholars also highlighted the ruling as an opportunity to transform Korea’s climate governance into a more transparent and accountable system. By establishing that national climate policies can be legally mandated, this precedent may inspire similar legal actions internationally and could lead to an increase in climate litigation. Ultimately, the decision is expected to contribute to international discussions on strengthening the legal enforceability of long-term climate goals, as it constitutionally recognizes intergenerational equity, a core principle of climate justice. - Title: South Korea's Landmark Ruling on Climate Justice - Authors: Gilwon Lee (Sungkyunkwan University), Taejung Park (KAIST) - Journal: Nature Human Behaviour (IF 22.3) Taejung Park (KAIST)
- No. 302
- 2025-04-21
- 354
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The Power of Figurative Language: Enhancing the Effectiveness of AI-Generated Travel Recommendations
Professor Tae Hyun Baek from SKKU’s Department of Media and Communication, in collaboration with research teams from the University of Strathclyde (UK) and Texas A&M University (USA), has published an international joint study in a top-tier SSCI journal in the field of hospitality and tourism. This research investigates how the linguistic style (figurative versus literal language) of generative AI affects consumers’ responses to travel destination recommendations. It offers practical insights into the design of AI-driven communication strategies in tourism marketing. The research was recently published in the International Journal of Hospitality Management, a top-tier Q1 SSCI journal ranked in the top 2.5% in the category of Hospitality, Leisure, Sport & Tourism (2023 Impact Factor of 10.0). Study 1 revealed that figurative language significantly increased participants’ visit intentions, with imagery vividness mediating the relationship between language style and visit intention. Study 2 demonstrated that the persuasive effect of figurative language was amplified among individuals who perceived ChatGPT as more human-like, indicating that perceived human-likeness moderates the figurative language effect. Study 3 showed that while figurative language enhanced visit intention when used by ChatGPT, the same effect was less pronounced when the recommendation came from a human agent, suggesting a fundamental difference in how language style operates depending on the recommendation agent type. Professor Baek commented, “With the rapid advancement of generative AI technologies, understanding how AI-generated recommendations influence consumer behavior is increasingly important. This study offers empirical evidence that language style matters—and that AI, when perceived as human-like, can be particularly persuasive.” He added, “These findings are especially relevant for K-tourism communication. Effectively leveraging AI tools like ChatGPT, particularly through figurative language, opens new possibilities for engaging international travelers.” The implications of this research extend beyond tourism marketing to local branding efforts. Municipal governments and tourism organizations can utilize generative AI to express regional identity and distinctiveness through figurative language, potentially enhancing destination appeal and inspiring stronger travel intentions among both domestic and international tourists. Professor Tae Hyun Baek is a leading scholar in digital advertising, artificial intelligence and consumer behavior, and media technology. He has published over 61 papers in internationally renowned journals and currently serves as Associate Editor of the Journal of Advertising Research (SSCI) and the Journal of Current Issues and Research in Advertising (ESCI, Scopus). Baek, T. H., Kim, H. J., & Kim, J. (2025). AI-generated recommendations: Roles of language style, perceived AI human-likeness, and recommendation agent. International Journal of Hospitality Management,126, 104106.
- No. 301
- 2025-04-15
- 492
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Development of a Kinetically Engineered Vaccine Mimicking Immune Responses from Natural Infection
A research team led by Professor Yong Taik Lim at the Sungkyunkwan Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, has developed a next-generation vaccine platform that mimics the multidimensional immune responses induced by natural infections, providing long-term and broad protection against various viral infections. In this study, the researchers successfully developed a Kinetically Engineered Vaccine (KE-VAC) that mimics the key immunological features of recovered patients. At the microscopic level, the team regulated the timing of action of Toll-like receptor (TLR) agonists, and at the macroscopic level, they controlled the supply kinetics of antigens and adjuvants, thereby inducing immune responses similar to those observed in natural infection. The vaccine enables prolonged activation of antigen-presenting cells (APCs) without exhaustion and enhances both antibody production and T cell responses by extending the interaction time within the lymph nodes. This research was published online in the world-renowned journal Nature Communications (IF = 14.7) on March 25, 2025. Conventional artificial vaccines primarily use single antigens or universal adjuvants such as aluminum (Alum) to induce stable antibody responses. However, they fall short of replicating the complex immune responses seen in natural infections, resulting in limited T cell activation and insufficient long-term protection. To overcome these limitations, the team designed a kinetically activated TLR7/8 agonist (m-TLR7/8a), which was encapsulated in nanoliposomes and formulated with Alum to enable gradual delivery of both antigens and immune signals to the lymph nodes. This formulation mimics the gradual replication of pathogens in vivo, successfully inducing sustained immune responses in lymph nodes for up to six weeks. The KE-VAC platform demonstrated strong humoral and cellular immune responses in animal models using model antigens such as OVA. Furthermore, in collaborative studies with the Korea Virus Research Institute (Director: Young Ki Choi) and the College of Veterinary Medicine at Chungnam National University (Professor Jong-Soo Lee), KE-VAC showed exceptional and long-lasting protective efficacy against spike proteins from SARS-CoV-2, the sM2HA2 antigen from influenza viruses, and the SFTS virus through both immune response analysis and survival studies. KE-VAC can simultaneously induce both antibody and T cell responses through a single formulation, making it a highly versatile immune platform that can be quickly adapted to emerging infectious diseases or viral variants. Its ability to replicate the depth and durability of immune responses observed in natural infection highlights its promise not only for infectious disease prevention but also for next-generation cancer vaccine development. Author: Sang Nam Lee (1st authof, Postdoctoral Researcher), Ryounho Eun (co-1st author, Researcher), Sei Hyun Park (Co-author, Ph.D student), Janghun Heo (Co-author, Ph.D student), Yong Taik Lim (Corresponding Author, Professor, Sungkyunkwan University) Title: Kinetically activating nanovaccine mimicking multidimensional immunomodulation of natural infection for broad protection against heterologous viruses in animal models (Nature Communications; IF=14.7, March 25, 2025)
- No. 300
- 2025-04-10
- 408
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Identifying the effectiveness of SGLT2 inhibitors
A research team led by Prof. Ju-Young Shin from the School of Pharmacy conducted a large-scale, population-based cohort study utilizing national health claims data to evaluate the effectiveness of sodium-glucose cotransporter 2 (SGLT2) inhibitors in preventing major hepatic events in patients with metabolic dysfunction-associated steatotic liver disease (MASLD). MASLD is an increasingly prevalent condition worldwide, with a particularly high prevalence of up to 60% among individuals with type 2 diabetes. Given that MASLD remains asymptomatic until it progresses to severe stages and that a multidisciplinary approach is crucial for delaying disease progression, there is an urgent need to explore effective antihyperglycemic therapies that can prevent major hepatic events, including decompensated cirrhosis, ascites, varices, liver failure, and liver transplantation, in patients with MASLD and concomitant type 2 diabetes. To address this need, Professor Shin’s team conducted a cohort study using the National Health Insurance Service (NHIS) claims database, including patients diagnosed with MASLD who were newly prescribed SGLT2 inhibitors, glucagon-like peptide-1 receptor agonists (GLP-1RAs), or thiazolidinediones (TZDs) between 2014 and 2022. The study compared the risk of major hepatic events across these treatment groups. The findings revealed no significant difference in hepatic event prevention between SGLT2 inhibitors and GLP-1RAs. However, compared to TZDs, SGLT2 inhibitors were associated with a 23% reduction in the risk of major hepatic events. Professor Shin emphasized, “Considering the close relationship between type 2 diabetes and MASLD, current clinical guidelines lack sufficient evidence to support a specific antihyperglycemic therapy for the prevention of major hepatic events in MASLD patients. This study is significant in that it directly compares the hepatic risks associated with SGLT2 inhibitors, GLP-1RAs, and TZDs, thereby generating critical evidence for clinical decision-making.” This research was supported by a grant from the Patient-Centered Clinical Research Coordinating Center (PACEN) funded by the Ministry of Health & Welfare, Republic of Korea. The study was conducted in collaboration with Professors Jae Hyun Bae and Young Min Cho from the Seoul National University Hospital, Professors Yoosoo Chang and Seungho Ryu from the Kangbuk Samsung Hospital, and Professor Christopher Byrne from the University of Southampton, UK. The findings were officially published in ‘Gut (Impact Factor=23.0, JCR rangking 2.4%)’ on January 17. ※ Title: Risk of hepatic events associated with use of sodium-glucose cotransporter-2 inhibitors versus glucagon-like peptide-1 receptor agonists, and thiazolidinediones among patients with metabolic dysfunction-associated steatotic liver disease ※ Journal: Gut(IF: 23.0) ※ Authors:Professor Ju-Young Shin, Dr. Sungho Bea, Miss. Hwa Yeon Ko Figure 1. The risk of hepatic decompensation events Figure 2. Cumulative incidence of hepatic decompensation events
- No. 299
- 2025-04-04
- 483
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Methodological Framework for Perovskite Solar Cells: A Collaborative with Nobel Laureate Moungi Bawendi
Professors Il Jeon and Jin-Wook Lee of SAINT, Sungkyunkwan University, in collaboration with Professor Moungi Bawendi, recipient of the 2023 Nobel Prize in Chemistry, have systematically established a comprehensive methodological framework for perovskite solar cells (PSCs). This pivotal research was recently published in Nature Reviews Methods Primers (Impact Factor: 50.1) on January 16, 2024 (DOI: https://doi.org/10.1038/s43586-024-00373-9). Professors Il Jeon and Jin-Wook Lee have been at the forefront of perovskite solar cell research, leading innovative advancements in the field. Prof. Jeon has pioneered the integration of microorganisms, self-healing polymers, and graphene into perovskite solar cell architectures, addressing fundamental challenges related to metal electrode substitution and lead-free alternatives—two critical barriers to PSC commercialization. His research has resulted in the world’s highest efficiency for metal-free PSCs and holds an officially certified national record for lead-free PSCs. This study was conducted with key contributions from Dr. Jiye Han (Research Professor at SAINT, Sungkyunkwan University), Dr. Geon-Woo Park (Postdoctoral Researcher in Prof. Jin-Wook Lee’s laboratory), and Dr. Shaun Tan (from Prof. Moungi Bawendi’s research group at MIT). This publication provides a comprehensive review of fabrication methodologies for high-performance perovskite solar cells, with an emphasis on the roles and properties of critical structural components, including the photoactive layer, charge transport layers, and electrode interfaces. Additionally, the study conducts an in-depth analysis of current technological limitations and offers strategic insights into future advancements in the field. This research was supported by the Korean Ministry of Science and ICT (MSIT), the National Research Foundation of Korea (NRF), the U.S. Department of Energy’s Energy Efficiency and Renewable Energy (EERE) program, the European Union’s Horizon 2020 Research and Innovation Program, and Germany’s Special Priority Program. ※ Title: Perovskite solar cells ※ Journal: Nature Reviews Methods Primers (IF: 50.1) ※ DOI: https://doi.org/10.1038/s43586-024-00373-9 ※ Authors: Dr. Jiye Han (Research Professor at SAINT, Sungkyunkwan University), Dr. Geon-Woo Park (Postdoctoral Researcher in Prof. Jin-Wook Lee’s laboratory), and Dr. Shaun Tan (from Prof. Moungi Bawendi’s research group at MIT), Prof. Yana Vaynzof (TU Dresden), Prof. Jingjing Xue (ZJU), Prof. Eric Wei-Guang Diau(NCTU), Prof. Moungi G. Bawendi (MIT), Prof. Jin-Wook Lee(SKKU Nano Engineering & SAINT), Prof. Il Jeon (SKKU Nano Enginnering & SAINT) ▲Figure 1: Schematic Representation of Perovskite Solar Cell Architecture and Operational Mechanisms
- No. 298
- 2025-03-28
- 804
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Transforming Petrochemical Industry with Eco-Friendly Biomaterials
Prof. Jin Woong Kim's team, collaborating with Prof. Bum Jun Park's team from Kyung Hee University and Cosmocos Co., Ltd., has identified the core mechanism of a nanocellulose-based catalytic system and demonstrated its potential as an eco-friendly petrochemical catalyst. Traditional desulfurization in petrochemical industries causes energy consumption and environmental pollution due to high-temperature, high-pressure conditions and extensive oxidizing agent use. The research team developed a charge-based self-assembling nanomesh structure using renewable nanocellulose that functions as an emulsion microreactor, enabling efficient, environmentally friendly desulfurization. The technology's core principle involves strong electrostatic adsorption between the emulsion interface's natural negative charge (-0.3 C/m²) and cationic nanocellulose (HNC+). This generates a powerful adsorption energy of -1,200 kBT, causing HNC+ to form a stable nanomesh network at the interface, providing superior stability compared to conventional systems. The nanomesh structure, with uniform ~34 nm pores, promotes selective biphasic diffusion. The catalytic complex formed by terminal positive charges and oxidizing agents achieves over 95% desulfurization activity. This microreactor maintains structural integrity under extreme conditions (pH 2-13, 1.8M NaCl, 90°C) and demonstrates excellent durability after repeated use. Prof. Kim stated, "This highly stable microreactor represents an innovative turning point that overcomes the limitations of existing catalyst systems dependent on high temperature, pressure, and cost," adding that "this achievement will serve as foundation technology for environmentally friendly processes and sustainable chemical industries." The technology has been patented (Application No.: R-2023-0964-KR-1) with Cosmocos Co., Ltd., showing potential for expansion in cosmetics, drug delivery, and functional coatings as an eco-friendly biodegradable emulsifier. This research was supported by the INNOPOLIS Foundation and the National Research Foundation of Korea and published in Advanced Materials (IF: 27.4) on March 18, 2025. ※ Title: Charge-Directed Nanocellulose Assembly for Interfacial Phase-Transfer Catalysis ※ Authors: Jaewon Shin (First Author), Bokgi Seo, Kyung-Ho Choi, DaAe Park, Hee Jung Lee, Dae Hyun Shin, Prof. Bum Jun Park (Corresponding Author), Prof. Jin Woong Kim (Corresponding Author) ※ Journal: Advanced Materials ※ Paper Link: doi.org/10.1002/adma.202418325
- No. 297
- 2025-03-25
- 714
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Unveiling the secret of how lipids regulate plant vacuoles
The research team led by Professor Sangho Lee in the Department of Biological Sciences (first author Dr. Yeongmok Lee) has uncovered the secret of how lipids regulate plant vacuoles through collaboration with scientists at the Institute for Plant Sciences of Montpellier (IPSiM) in France, the Department of Physics at Sungkyunkwan University and the Korea Basic Science Institute (KBSI). The team determined various structures of aluminum-activated malate transporter 9 (ALMT9) anion channel and proposed its structure-based activation mechanism. Plant vacuoles are pivotal in storing and distributing various substances, thereby regulating stress resistance, volume, and other physiological processes. Diverse ion channels and transporters regulate the movement of substances in and out of vacuoles. Among them, the ALMT9 is reported to mediate crucial functions such as stomatal regulation and key determinants of fruit flavor. The research team discovered unexpected lipid-bound states in various ALMT9 structures. Beyond structural analysis, collaboration with experts in mass spectrometry, electrophysiology, and molecular dynamics elucidated the crucial role of lipids in regulating ALMT9. This study sheds light on the roles of lipids in vacuolar regulation, paving the way for future research. Prof. Sangho Lee remarked, "Through this study, the mystery of lipid function in regulating ALMT9 has finally been unveiled. This knowledge opens new frontiers in exploring the roles of lipids in biological phenomena." He also said, “It shows a research case using cryo-EM, a state-of-the-art device recently introduced in our university, emphasizing its potential for producing outstanding research outcomes.” The research was published online in Nature Communications (IF: 14.7) on February 20th. ※ Title: Structural basis for malate-driven, pore lipid-regulated activation of the Arabidopsis vacuolar anion channel ALMT9 ※ DOI: https://doi.org/10.1038/s41467-025-56940-5 ※ Author: Ph.D. Yeongmok Lee (first author), Jaemin Yoo, Seoyeon Jung, Prof. Jejoong Yoo, Prof. Sangho Lee (corresponding author) Figure 1. ALMT9 anion channel structures in various lipid-bound states
- No. 296
- 2025-03-21
- 339
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Transparent OLED Device Capable of Displaying Different Information in Both Directions
Professor Jang-Kun Song's research team from the Department of Display Engineering demonstrated a transparent OLED display capable of displaying different information in both directions by integrating a Yb-Ag transparent electrode with work function control properties and excellent surface characteristics, along with a novel pixel arrangement. Transparent displays are one of the most advanced display technology fields in which South Korea leads globally. At last year’s CES exhibition in Las Vegas, LG Display’s transparent OLED was selected as the best product of CES. However, transparent displays have yet to secure a killer application and are currently applied only in niche markets. The biggest advantage of transparent displays is their ability to provide information while maintaining a sense of spatial openness. Development of core technologies and application products that fully leverage this advantage is essential for expanding the transparent display market. For example, if a transparent display can provide different information to two people facing each other while not obstructing their view, it could play a crucial role in various environments such as education, meetings, consultations, and customer service. To achieve this, advanced transparent electrode technology and a display pixel structure capable of displaying bidirectional information with a minimal increase of pixels are required. Professor Jang-Kun Song’s research team, including his master course student Eun-Young Choi, developed a Yb-Ag alloy electrode with high transparency, high conductivity, extremely low surface roughness, and work function tunability. They successfully demonstrated a transparent display incorporating this electrode. Additionally, they developed a technology that separates the areas with opaque TFTs from those without, enabling independent operation of single-directional and bidirectional information display pixels, allowing the display of different information in both directions. The newly developed bidirectional transparent display technology can also adjust the relative brightness on both sides. Therefore, it can be used for a bidirectional transparent displays on a store window, where the ambient brighness inside the store is much different from that outside. This capability makes it a crucial technology for expanding the transparent display market. This research was supported by Korea Institute for Advancement of Technology(KIAT) grant funded by the Korea Government(MOTIE) under HRD Program for Display Industrial Innovation and by the Ministry of Education’s Basic Research Laboratory Program. The research findings were published in Light: Science & Applications (IF: 20). ※ Paper Title: Transparent OLED displays for selective bidirectional viewing using ZnO/Yb:Ag cathode with highly smooth and low-barrier surface ※ Journal: Light: Science & Applications ※ D.O.I: https://doi.org/10.1038/s41377-024-01739-0 ▲ (Top)A transparent electrode with high transmittance and low surface roughness using a Yb:Ag alloy, (Middle)Various display modes based on pixel arrangement and operation—front display mode, identical image display on both sides, and different image display on the front and back, (Bottom) The driving circuit and image signal application method used to achieve these display functions
- No. 295
- 2025-03-18
- 774
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Prof. Choi’s Research Team Observes 1/9 Magnetization Plateau and Dirac Spinon Quasiparticles in aKagome Spin Lattice
Quantum spin liquids (QSLs) differ from conventional magnetic materials in that they do not exhibit long-range magnetic order even at absolute zero temperature. Instead, spins in QSLs remain highly entangled, giving rise to topologically protected quantum states. The kagome lattice, a two-dimensional network of edge-sharing triangles, is particularly prone to geometric frustration, which prevents conventional spin alignment and promotes strong quantum fluctuations. These characteristics make kagome spin systems ideal platforms for exploring exotic quantum phases, including quantum spin liquids and field-induced magnetization plateaus. In this study, the research team successfully observed the 1/9 magnetization plateau in the copper-based kagome compound YCu3(OD)₆+xBr3−x under a strong magnetic field of 15 T. By combining thermodynamic measurements (specific heat, thermal conductivity, and pulsed-field magnetization) with Raman spectroscopy, they identified Dirac spinon quasiparticles, raising the possibility that the plateau state may be linked to an unconventional quantum phase, potentially a Z3 spin liquid. Professor Kwang-Yong Choi stated, "The realization of the 1/9 magnetization plateau in a kagome spin lattice under applied magnetic fields marks a breakthrough in the study of novel quantum materials. This research is expected to contribute to future applications in quantum computing, particularly in the development of highly stable qubits and topological quantum computation based on spin liquid states.“ This research was conducted in collaboration with Dr. Dirk Wulferding and Dr. Sungkyun Choi from the Institute for Basic Science (IBS), as well as Professor Ki-Hoon Kim’s team at Seoul National University. The study was supported by the National Research Foundation of Korea (NRF) and was published online in Nature Physics (Impact Factor: 18.1, JCR Top 5%) on January 12, 2024. Furthermore, it was featured in Nature Physics' "News &Views" section on February 12, 2024, under the title "A kagome antiferromagnet reaches its quantum plateau.“ ※ Title: One-ninth magnetization plateau stabilized by spin entanglement in a kagome antiferromagnet ※ Link: https://www.nature.com/articles/s41567-023-02318-7 Illustration and observation of Dirac spinons in the kagome lattice and the 1/9 magnetization plateau in the magnetization curve
- No. 294
- 2025-03-13
- 873
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Sungkyunkwan University develops Next-Generation Encryption Technology with van der Waals Topological Insulators
Professor Taesung Kim’s research team in the Department of Mechanical Engineering at Sungkyunkwan University (President Ji-Bum Yoo) has collaborated with Professor Seok-Joon Kwon’s research team to develop next-generation encryption technology based on Physically Unclonable Function (PUF) which was achieved by identifying the randomly generated lattice symmetry-breaking characteristics within van der Waals topological insulators. PUF utilize the random physical variations occurring during the semiconductor manufacturing process to generate unique, physically unclonable identification keys. Considered highly secure, hardware-based encryption technologies, PUF are suitable for small Internet of Things (IoT) devices. However, conventional PUF have limitations as they require more complex hardware structures to increase the number of security key combinations. To overcome this, the research team focused on the unique characteristics of van der Waals topological insulators. A topological insulator is a material that behaves as an insulator internally but conducts electricity on its surface, making it highly useful in quantum computing research. In van der Waals topological insulators, inversion symmetry in the crystalline structure is broken, leading to a topological state with metallic properties on the surface. The research team employed a low-temperature plasma process to sulfurize the top layer of the material, inducing asymmetric lattice structures and randomly distributed ferroelectric domains. These domains exhibited spontaneous polarization, enabling the development of a self-powered, high-security PUF device. The research demonstrated that the PUF device achieved an optimal level of randomness, with a probability of approximately 0.5012 for generating “1” in a binary sequence. This randomness level is crucial for ensuring encryption security. Additionally, the research team verified that the size of the ferroelectric domains and the PUF device could be controlled by adjusting the plasma process parameters. Piezoelectric force microscopy (PFM) was utilized to validate the device’s reliability and reproducibility. The low-temperature plasma process also allows for large-area synthesis with shorter production times, making the technology highly scalable and suitable for commercial mass production. Professor Kim explained, "This next-generation quantum encryption technology, leveraging lattice symmetry- breaking characteristics in van der Waals topological insulators, enables self-powered, high-security encryption with a low-temperature plasma process. It will be a key foundational technology for future artificial intelligence and quantum security platforms.“ The research was supported by the National Research Foundation of Korea (NRF) and the Institute for Basic Science (IBS). The findings were published in Advanced Materials, one of the world’s leading journals in materials science, on February 18th. ※ Title: Stochastically Broken Inversion Symmetry of Van der Waals Topological Insulator for Nanoscale Physically Unclonable Functions ※ Journal: Advanced Materials (IF: 29.6, Top 1% JCR) ※ Link: https://advanced.onlinelibrary.wiley.com/doi/10.1002/adma.202419927 Schematic of stochastically broken inversion symmetry of van der Waals topological insulator
- No. 293
- 2025-03-07
- 510
