Research

Ribosome Hooks a 'Ring' onto Proteins After Billions of Years

[POSTECH Achieves First-Ever Ribosomal Synthesis of Cyclic Peptides : Opening New Avenues for Next-Generation Drug Design] Inside our cells, ribosomes-the tireless “protein factories” of life-have just shown off a new skill they haven’t used in billions of years. A research team led by Professor Joongoo Lee in the Department of Chemical Engineering at POSTECH (Pohang University of Science and Technology) has become the first in the world to successfully expand the range of ring-shaped backbones in proteins using ribosomes, which have traditionally only produced linear backbones. The breakthrough was recently published in the online edition of the prestigious scientific journal Nature Communications. Ribosomes are essential molecular machines found in all living organisms on Earth. Like a master builder snapping together LEGO blocks, they assemble amino acids (tiny molecular components) into the proteins our bodies need. They can join about 20 amino acids per second, a speed tens of thousands of times faster than is achievable through conventional chemical synthesis in a lab. However, since the dawn of life on Earth, ribosomes have only ever made proteins in a long, noodle-like linear backbone. These linear peptide bacbones, are relatively fragile and not particularly good at binding to specific targets like viruses, bacteria, or cancer cells, making them less effective as therapeutic drugs. In contrast, ring-shaped bacbones are more stable, more durable, and bind more tightly to their targets, but are notoriously difficult and complex to produce chemically. Inspired by the fact that many natural antibiotics like penicillin contain ring-shaped structures, the POSTECH team asked a bold question: Could ribosomes be coaxed into making these rings themselves? Rather than modifying the ribosome itself, the researchers engineered a new set of building blocks, 26 specially designed amino acids. These new amino acids naturally attract each other inside the ribosome, forming rings during the protein-making process. Using a cell-free protein synthesis*1 system, the team demonstrated that ribosomes could now produce not just linear chains, but also core ring structures such as pentagons and hexagons. Remarkably, these reactions occurred under simple, biological conditions at 37°C and pH 7.5, using the ribosome’s original mechanisms, with no external intervention. This isn’t the first time Professor Lee’s team has broken new ground. In 2022, in collaboration with Northwestern University and the University of Texas, they were the first to report that ribosomes could be used to create proteins containing six-membered rings; something never before observed in their billions of years of evolutionary history. This new study significantly expands the possibilities, introducing a wider range of materials and demonstrating that ribosomes can now form both five- and six-membered rings. Even more remarkably, the ring-formation process can be finely controlled by adjusting the design of the special amino acids. The implications are significant. This could open the door to using ribosomes as catalysts for novel chemical reactions, paving the way for next-generation therapeutics and advanced biomaterials. “What struck me the most,” said Professor Lee, “was how similar the reactions inside the ribosome were to the chemical processes we learned in our textbooks. If we can figure out how the ribosome’s 4,500 components work together to perform what seems like molecular magic, it could deepen our understanding of both life and evolution.” This research was supported by the Outstanding Young Scientist Grants, the Core Technology Development Program for Synthetic Biology, and the Hanwumul‑Phagi Basic Research Project of the Ministry of Science and ICT. DOI: https://doi.org/10.1038/s41467-025-60126-4 1. Cell-Free Protein Synthesis (CFPS) : An artificial biosynthesis system that enables the synthesis of proteins or peptides in vitro without the use of living cells.

"Fluorescence ON in Cancer Cells Only" – Diagnosing Cancer with Light

[POSTECH and Linyi University develop ‘SLY,’ a Probe That Glows Yellow Only in Tumor Cells] A collaborative research team led by Professor Young-Tae Chang from the Department of Chemistry at Pohang University of Science and Technology (POSTECH) and Professor Min Gao from Linyi University has successfully developed a novel fluorescent probe, SLY (Sialyl Lewis Yellow), capable of precisely identifying hepatocellular carcinoma tissue. The findings were published in the Journal of the American Chemical Society (JACS), a leading journal published by the American Chemical Society. Glycans—carbohydrate structures present on the surface of cells—play pivotal roles in various biological processes, including cell-cell interactions, immune responses, and cancer metastasis. Among these, the sialyl Lewis family of glycans, particularly sialyl Lewis x (sLex) and sialyl Lewis a (sLea), are known to be overexpressed in several types of cancers, including liver cancer, positioning them as promising diagnostic markers. However, conventional techniques for analyzing glycans are complex and generally unsuitable for real-time imaging, underscoring the urgent need for fluorescent probes that can directly detect glycans in living cells. The research team designed a library of fluorescent probes incorporating oxaborole as a recognition moiety and identified SLY as a probe capable of selectively targeting sialylated glycans on the cell surface. SLY demonstrated high affinity for sLex and sLea, which are overexpressed in hepatocellular carcinoma (HepG2) and colorectal cancer (HT29) cells. After binding to the target glycans, SLY is internalized via caveolae-mediated endocytosis and accumulates in the mitochondria. In vivo and ex vivo experiments using cryo-sectioned liver cancer tissues confirmed the probe’s ability to selectively label cancerous regions with high fluorescence contrast. Notably, SLY outperforms conventional probes by clearly distinguishing tumor margins within liver tissues, suggesting strong potential for use in precision diagnostics and fluorescence-guided surgery. Professor Young-Tae Chang, who led the study, commented, “SLY represents the first fluorescent probe capable of selectively identifying sialylated glycans on the cell surface with such precision, enabling the identification of liver cancer at the cellular level. This work opens new possibilities in glycan-based cancer diagnostics and may lay the groundwork for future applications in fluorescence-guided surgery and precision medicine.” This research was supported by the National Research Foundation of Korea (NRF) under the Ministry of Science and ICT through the Mid-Career Researcher Program and the Glocal University 30 initiative (POSTECH Molecular Imaging Center). Additional support was provided by the TIPS program of the Ministry of SMEs and Startups (Korea), the National Natural Science Foundation of China, the Shandong Overseas High-Level Talent Program, and the Taishan Scholar Program. DOI: https://pubs.acs.org/doi/10.1021/jacs.5c03020

Shape Memory Polymer Dry Adhesive Technology Paves the Way for Micro-LED Innovation

[POSTECH Researchers Develop Smart Adhesive Surfaces: Firm When Stuck, Clean and Easy When Released] A research team at Pohang University of Science and Technology (POSTECH), led by Professor Seok Kim in collaboration with Professor Kihun Kim (POSTECH), Professor Namjoong Kim (Gachon University), Professor Haneol Lee (Chonbuk National University), and Dr. Chang-Hee Son (University of Connecticut, USA), has developed a novel dry adhesive technology that allows everything from microscale electronic components to common household materials to be easily attached and detached. The study was recently published in the prestigious journal Nature Communications. Micro-LEDs, a next-generation display technology, offer significant advantages such as higher brightness, longer lifespan, and the ability to enable flexible and transparent displays. However, transferring micro-LED chips—thinner than a strand of hair—onto target substrates with high precision and minimal residue has been a persistent challenge. Conventional methods relying on liquid adhesives or specialized films often result in overly complex processes, poor alignment accuracy, and residual contamination. In addition, researchers have struggled with the so-called adhesion paradox—the theoretical prediction that surfaces should strongly adhere at the atomic level, contrasted by the real-world difficulty of achieving strong adhesion due to surface roughness that limits actual contact area. The POSTECH team ingeniously leveraged this paradox. Their solution lies in the use of shape memory polymers (SMPs) featuring densely packed nanotips. At room temperature, the surface remains rough, exhibiting low adhesion. When heated and pressed, the surface smooths out—much like ironing wrinkles—and achieves significantly stronger adhesion. Upon reheating, the surface returns to its original rough state, drastically reducing adhesion and enabling easy release. This technology provides over 15 atmospheres of adhesion strength during bonding and near-zero force detachment through a self-release function. The difference in adhesion strength between the "on" and "off" states exceeds a factor of 1,000, outperforming conventional approaches by orders of magnitude. The team demonstrated precise pick-and-place of micro-LED chips using a robotic system, and confirmed stable adhesion even with materials such as paper and fabric. “This innovation allows for the precise manipulation of delicate components without the need for sticky adhesives,” said Professor Seok Kim of POSTECH. “It holds significant potential for applications in display and semiconductor manufacturing, and could bring about transformative changes when integrated with smart manufacturing systems across various industries.” This research was supported by the Ministry of Science and ICT of Korea. DOI: https://doi.org/10.1038/s41467-025-60220-7

Ancient Golden Silk Revived from the Korean Sea

[POSTECH research team recreates sea silk from discarded pen shells byssus—drawing attention as an eco-friendly and sustainable textile] A luxurious fiber once reserved exclusively for emperors in ancient times has been brought back to life through the scientific ingenuity of Korean researchers. A team led by Professor Dong Soo Hwang (Division of Environmental Science and Engineering / Division of interdisciplinary bioscience & bioengineering, POSTECH) and Professor Jimin Choi (Environmental Research Institute) has successfully recreated a golden fiber, akin to that of 2,000 years ago, using the pen shell (Atrina pectinata) cultivated in Korean coastal waters. This breakthrough not only recreates the legendary sea silk but also reveals the scientific basis behind its unchanging golden color. The study was recently published in the prestigious journal Advanced Materials. Sea silk—often referred to as the “golden fiber of the sea”—was one of the most prized materials in the ancient Roman period, used exclusively by figures of high authority such as emperors and popes. This precious fiber is made from the byssus threads secreted by Pinna nobilis, a large clam native to the Mediterranean, which uses the threads to anchor itself to rocks. Valued for its iridescent, unfading golden color, light weight, and exceptional durability, sea silk earned its reputation as the “legendary silk.” A notable example is the Holy Face of Manoppello, a relic preserved for centuries in Italy, which is believed to be made from sea silk. However, due to recent marine pollution and ecological decline, Pinna nobilis is now an endangered species. The European Union has banned its harvesting entirely, making sea silk an artifact of the past—produced only in minuscule quantities by a handful of artisans. The POSTECH research team turned their attention to the pen shell Atrina pectinata, a species cultivated in Korean coastal waters for food. Like Pinna nobilis, this clam secretes byssus threads to anchor itself, and the researchers found that these threads are physically and chemically similar to those of Pinna nobilis. Building on this insight, they succeeded in processing pen shell byssus to recreate sea silk. However, their achievement goes beyond mere replication of its appearance. The team also revealed the scientific secret behind sea silk’s distinctive golden hue and its resistance to fading over time. The golden color of sea silk is not derived from dyes, but from structural coloration—a phenomenon caused by the way light reflects off nanostructures. Specifically, the researchers identified that the iridescence arises from a spherical protein structure called “photonin,” which forms layered arrangements that interact with light to produce the characteristic shine. Similar to the color seen in soap bubbles or butterfly wings, this structure-based coloration is highly stable and does not fade easily over time. Moreover, the study revealed that the more orderly the protein arrangement, the more vivid the structural color becomes. Unlike traditional dyeing, this color is not applied but instead generated by the alignment of proteins within the fiber, contributing to the material’s remarkable lightfastness over millennia. Another significant aspect of this research is the upcycling of pen shell byssus, previously discarded as waste, into a high-value sustainable textile. This not only helps reduce marine waste but also demonstrates the potential of eco-friendly materials that carry cultural and historical significance. Professor Dong Soo Hwang noted, “Structurally colored textiles are inherently resistant to fading. Our technology enables long-lasting color without the use of dyes or metals, opening new possibilities for sustainable fashion and advanced materials.” DOI: https://doi.org/10.1002/adma.202502820

In an Era Where Empathy Feels Unfamiliar, AI Now Translates Emotions

[POSTECH Develops Personalized Emotion Translation AI 'EmoSync'… Ranks in Top 5% at International Conference] A research team at POSTECH (Pohang University of Science and Technology, South Korea) has developed AI technology that helps individuals deeply understand others' emotions by analyzing individual personality traits and values and generating personalized analogy. This study was recognized with the "Popular Choice Honorable Mention Award," given to the top 5% of 74 Interactivity track demonstrations at ACM CHI 2025, the world's leading international conference in Human-Computer Interaction (HCI). Society is a complex community where people with different identities and diverse backgrounds live together. While people strive to understand each other, even the concept of "empathy" can sometimes feel overwhelming - because even in the same situation, emotions can differ greatly from person to person. Until now, computer-based empathy technologies have been operating on the assumption that showing the same experience would evoke similar emotions. However, reality is more complicated: emotional reactions vary widely depending on an individual's personality, past experiences, and values. "EmoSync", an LLM-based agent, embraces and utilizes these individual differences. By meticulously analyzing each user's psychological traits and emotional response patterns, the LLM generates personalized analogical scenarios that allow people to understand others' feelings through the lens of their own experiences. For example, if a user struggles to empathize with subtle discrimination or exclusion in the workplace, EmoSync analyzes the user's past experiences and creates a relatable connection, such as ‘a moment of feeling excluded by peers during school days.’ This approach helps users understand others' emotions more vividly and realistically by using the lens of familiar experiences. The research team conducted experiments involving over 100 participants from diverse backgrounds using this technology. The results showed that participants who used EmoSync demonstrated significantly improved emotional understanding and empathy compared to traditional methods. This scientifically demonstrates that personalized metaphorical experiences can genuinely enhance empathy. Hyojin Ju, the first author of the study, said, "Our research demonstrates that AI can be used to facilitate genuine understanding and empathy among people," and added, "We will continue to develop AI technologies that help foster true understanding and empathy in real-life situations." Professor Inseok Hwang of POSTECH commented, "This study is a successful example showing that generative AI can identify each user's unique emotional structure and generate personalized experiences that induce specific emotions. It represents a novel and meaningful approach-both academically and socially-to fostering empathy in ways that were not possible before." This research was conducted by Professor Inseok Hwang and Ph.D. students Hyojin Ju, Jungeun Lee, and Seungwon Yang from POSTECH's Department of Computer Science and Engineering, in collaboration with Professor Jungseul Ok. The project was supported by the National Research Foundation of Korea (NRF) Mid-career Researcher Program, the Future Convergence Technology Pioneer Project funded by the Korean government (MSIT), and the University ICT Research Center Project from the Institute of Information & Communications Technology Planning & Evaluation (IITP), also funded by the Korean government (MSIT). DOI: https://doi.org/10.1145/3706598.3714122

3D Printed Brain Sheds Light on Neurological Disorders

[POSTECH Research Team Reproduces Neural Signal Transmission and Degenerative Responses Using a 3D Printed Brain Model] A research team led by Professor Dong-Woo Cho (Department of Mechanical Engineering, POSTECH) and Professor Jinah Jang (Departments of Mechanical Engineering, IT Convergence Engineering, Life Sciences, and Interdisciplinary Graduate Program), in collaboration with Dr. Mihyeon Bae, and Dr. Joeng Ju Kim, has successfully developed a three-dimensional (3D) brain model that closely mimics the structure and function of the human brain. The study was published in the International Journal of Extreme Manufacturing, a leading journal in the field of manufacturing and materials science. Neurodegenerative diseases such as Alzheimer’s and Parkinson’s are notoriously difficult to reverse once they onset occurs, making early diagnosis and predictive modeling critically important. However, the brain is the most complex organ in the human body, with intricately interconnected cells and signaling mechanisms that remain largely unexplored. Recent studies have suggested that even everyday alcohol consumption may be linked to neural damage, further emphasizing the urgent need for in vitro brain models that can precisely replicate human brain responses in laboratory settings. Existing two-dimensional cell cultures and stem cell-derived organoids have shown significant limitations in reproducing the complex architecture and function of the brain. To overcome these limitations, the POSTECH research team developed the Bioengineered Neural Network (BENN)—a novel 3D artificial brain model constructed layer by layer, akin to building a house using a 3D printer. A central innovation of this model lies in the biomimetic compartmentalization into two distinct regions: gray matter, which contains neuronal cell bodies, and white matter, which consists of aligned axons that act as information highways facilitating signal transmission. The researchers applied electrical stimulation to guide the axonal growth of neurons in a specific direction, promoting the formation of aligned and interconnected neural pathways. This led to the establishment of a functional neural network that closely resembles the brain's native signal transmission architecture. Real-time monitoring of calcium ion flux confirmed that the BENN model exhibited electrophysiological responses analogous to those observed in actual brain tissue. Furthermore, the team utilized the BENN platform to investigate the effects of alcohol exposure on brain function. The model was treated daily with ethanol at a concentration of 0.03%—representative of moderate social drinking—for three weeks. In the gray matter region, they observed elevated levels of Alzheimer’s-related proteins, including amyloid-beta and tau. In the white matter, they identified significant morphological changes in neural fibers, including swelling and distortion. The propagation of neural signals also exhibited marked attenuation. This study is the first to directly visualize and quantify region-specific neurotoxic responses to alcohol in real time using a bioengineered brain model. Professor Dong-Woo Cho stated, “This model enables high-resolution analysis of neural connectivity and electrophysiological responses that were previously difficult to observe. It holds significant potential for early disease detection and accurate prediction of therapeutic outcomes at the preclinical stage.” Professor Jinah Jang added, “This research marks an important step forward in our ability to investigate the early pathological events of brain diseases in a laboratory setting.” This research was supported by Korean Fund for Regenerative Medicine funded by Ministry of Science and ICT, and Ministry of Health and Welfare (22A0106L1, Republic of Korea) and the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2022M3C1A3081359). DOI: https://doi.org/10.1088/2631-7990/add632

POSTECH Solves Core Challenge in Stretchable Displays with Uniform Multi-Pixel Strain Control

[POSTECH Develops World’s First Uniform Multi-Pixel Stretching Technology for Stretchable Displays Research featured on the Back Cover of Advanced Functional Materials] A research team at POSTECH (Pohang University of Science and Technology), led by Professor Su Seok Choi from the Department of Electrical Engineering and Ph.D. candidate Jun Hyuk Shin, has successfully developed the world’s first technology that enables uniform and even stretching across multiple pixels in a stretchable display. This breakthrough overcomes a critical challenge in the field and has been selected as a Back Cover article in the prestigious international journal Advanced Functional Materials. Global Race Toward Shape-Deformable Displays Display technology is currently undergoing a global transformation, with intense competition surrounding shape-deformable devices. Innovations such as foldable, bendable, and slidable displays have already emerged, and now attention is rapidly shifting—especially in South Korea—toward stretchable displays, which go beyond simple curvature and can physically expand. Stretchable displays are expected to evolve into next-generation devices that integrate with sensors to form electronic skin-like systems, capable of mimicking the flexibility and softness of human skin. For this direction, ideally fully and intrinsically stretchable technolgy with uniform control is highly desired. The Limitations of Existing Stretchable Display Technologies Most existing stretchable technologies rely on an extrinsic approach, using rigid electronic components connected by wavy or serpentine interconnects. While this allows some degree of mechanical deformation, it comes with significant trade-offs—limited stretching range, reduced pixel density, and degradation in display uniformity and image quality under strain. In contrast, the intrinsic approach, which uses materials like silicone or rubber that are inherently stretchable, is considered the ideal path forward. However, such systems have struggled with non-uniform strain distribution, particularly in multi-pixel arrays. As each pixel experiences a different degree of deformation depending on its location, this leads to inconsistencies in color, brightness, and signal transmission. This issue is fundamentally rooted in geometry and physics: when a stretchable material is pulled, areas farther from the point of tension receive less strain—similar to how the center of a rubber band or melted cheese stretches more than its edges. So far, achieving uniform stretching across all pixels in an intrinsically stretchable system has remained a critical and unsolved problem. Uniform & Even Stretching with Multi-Pixel Operations : Kirigami-Inspired Mechanical Design with Strain Stopper Integration To overcome this challenge, the POSTECH team drew inspiration from kirigami, the traditional Japanese art of paper cutting. By introducing finely patterned incisions on the surface of the stretchable substrate, they were able to evenly distribute mechanical stress during stretching. As a result, they successfully achieved uniform stretching up to 200% (twice the original length) in all areas of a 7×7 pixel array. Additionally, the researchers implemented a “strain stopper”—a rigid structure embedded in specific areas of the material—to suppress undesired deformation in certain directions. This marks the first successful demonstration of fully controlled, uniform, multi-directional stretching across a multi-pixel stretchable display system. Expansion to Optical Encryption Using CLCE Materials, which are intrinsically stretchable & color-changeable The team further integrated a chiral liquid crystal elastomer (CLCE)—an intrinsically stretchable and also mechanochromic material that changes color in response to mechanical stress. By combining CLCEs with their kirigami-structured platform, they developed a stretchable display capable of revealing hidden patterns only when stretched, a feature with strong potential in encryption and anti-counterfeiting applications. The CLCEs also exhibit circular polarization selectivity, enabling high-level optical security. When paired with a polarization filter, the display shows different colors or patterns depending on the viewing angle, allowing for dynamic, angle-dependent, secure information display. This technology could enable encrypted displays that are invisible to the naked eye but detectable using special optical equipment. Toward Real-World Applications This research not only solves a long-standing mechanical issue in stretchable displays but also opens doors to new applications in wearable electronics, flexible displays, and data security. By demonstrating a working system that combines uniform mechanical performance and advanced optical functionality, the team provides a foundation for future commercial stretchable devices. Professor Su Seok Choi commented, “By addressing the challenge of non-uniform deformation, this work greatly enhances the practical potential of intrinsically stretchable materials such as silicone, rubber, and artificial skin. It will also contribute significantly to the development of stretchable optical components and secure display technologies.” National R&D Support The study was supported by the Samsung Science and Technology Foundation and the Korea Evaluation Institute of Industrial Technology (KEIT) through the Stretchable Display Development and Demonstration Program. DOI: https://doi.org/10.1002/advs.202414691 Key Highlights: • POSTECH developed the world’s first intrinsically stretchable display with uniform multi-pixel deformation across a 7×7 array. (Overcome current inhomogeneity problem in stretchable technologies) • Introduced a kirigami-inspired mechanical design and integrated strain stoppers for fully controlled, direction-independent even stretching up to 200%. • Integrated chiral liquid crystal elastomers (CLCEs) for mechanochromic color changes and polarization-dependent optical encryption. • Enables encrypted displays that reveal hidden patterns only under mechanical strain and specific polarization views. • Demonstrated on a functional platform, paving the way for wearable electronics, electronic skin, secure flexible displays, and anti-counterfeiting technologies. • Featured as a Back Cover Article in Advanced Functional Materialsfor its scientific and technological significance.

An Iron Oxide ‘Oxygen Sponge’ for Efficient Thermochemical Hydrogen Production

As the world shifts toward sustainable energy sources, "green hydrogen"—hydrogen produced without emitting carbon—has emerged as a leading candidate for clean power. In a significant step forward, a collaborative research team led by Professor Hyungyu Jin from the Department of Mechanical Engineering at POSTECH and Professor Jeong Woo Han from the Department of Materials Science and Engineering at Seoul National University has developed a new iron-based catalyst that more than doubles the conversion efficiency of thermochemical green hydrogen production. Their findings were recently published in the journal Acta Materialia. With growing concerns over fossil fuel–driven pollution and climate change, hydrogen is gaining attention as a clean energy carrier that only emits water upon combustion. Among various hydrogen production pathways, thermochemical water splitting—which uses thermal energy to split water into hydrogen and oxygen—is considered particularly promising. Central to this process is the role of metal oxides, which absorb and release oxygen in cycles, effectively acting like “oxygen sponges.” However, most conventional oxides suffer from a key limitation: they require extremely high temperatures to operate effectively due to their thermodynamic characteristics. This has hindered their commercial viability. To address this challenge, the research team developed a novel iron-poor nickel ferrite (Fe-poor NiFe2O4, or NFO). While traditional oxides typically rely on non-stoichiometric reactions that allow relatively small oxygen absorption and release, the Fe-poor ferrite exhibits a distinct phase transformation mechanism that enables significantly greater oxygen capacity even at lower temperatures. Experimental results showed that the novel oxides achieved a water-to-hydrogen conversion efficiency of 0.528% per gram of oxides—more than double the 0.250% benchmark set by the previous best-performing material. What makes this study particularly noteworthy is not only the development of a high-efficiency catalyst, but also the team's success in unraveling the underlying mechanisms. Using a combination of experimental techniques and computational simulations, the researchers were able to identify, for the first time, the “structural active sites” within iron oxide materials that drive hydrogen production at the atomic level. They further revealed that a redox swing between two types of iron sites is directly correlated with hydrogen yield—an insight that could guide the future design of even more effective catalysts. “This study is meaningful in that it proposes an economical and sustainable hydrogen production pathway using abundant iron oxides,” “It also opens the door to using solar heat or industrial waste heat as energy sources for hydrogen generation” said Professor Hyungyu Jin. Professor Jungwoo Han added, “This work is a compelling example of how experimental and computational sciences can work together to uncover fundamental principles through interdisciplinary collaboration.” This research was supported by the Circle Foundation for Innovation Science and Technology Program, the National Research Foundation of Korea, and the Korea Institute of Materials Science. DOI: https://doi.org/10.1016/j.actamat.2025.121023

The Magic of Light: Dozens of Images Hidden in a Single Screen

[POSTECH Team unveils new technology that uses light’s color and spin to display multiple images] From smartphones and TVs to credit cards, technologies that manipulate light are deeply embedded in our daily lives, many of which are based on holography. However, conventional holographic technologies have faced limitations, particularly in displaying multiple images on a single screen and in maintaining high-resolution image quality. Recently, a research team led by Professor Junsuk Rho at POSTECH (Pohang University of Science and Technology) has developed a groundbreaking metasurface technology that can display up to 36 high-resolution images on a surface thinner than a human hair. This research has been published in Advanced Science, a leading journal in materials science and nanotechnology. This achievement is driven by a special nanostructure known as a metasurface. Hundreds of times thinner than a human hair, the metasurface is capable of precisely manipulating light as it passes through. The team fabricated nanometer-scale pillars using silicon nitride, a material known for its robustness and excellent optical transparency. These pillars, referred to as meta-atoms, allow for fine control of light on the metasurface. A remarkable aspect of this technology is its ability to project entirely different images depending on both the wavelength (color) and spin (polarization direction) of light. For example, left-circularly polarized red light may reveal an image of an apple, while right-circularly polarized red light may produce an image of a car. Using this technique, the researchers successfully encoded 36 images at 20 nm intervals within the visible spectrum, and 8 images spanning from the visible to the near-infrared region—all onto a single metasurface. What makes this innovation particularly notable is not only its simplified design and fabrication process, but also its enhanced image quality. The team addressed previous issues of image crosstalk and background noise by incorporating a noise suppression algorithm, resulting in clearer images with minimal interference between channels. “This is the first demonstration of multiplexing spin and wavelength information through a single phase-optimization process while achieving low noise and high image fidelity,” said Professor Rho. “Given its scalability and commercial viability, this technology holds strong potential for a wide range of optical applications, including high-capacity optical data storage, secure encryption systems, and multi-image display technologies.” This research was supported by the POSCO Holdings N.EX.T Impact Program, as well as the Pioneer Program for Converging Technology of the National Research Foundation of Korea, funded by the Ministry of Science and ICT. DOI: https://doi.org/10.1002/advs.202504634

Nature-Inspired Breakthrough Enables Subatomic Ferroelectric Memory

[POSTECH, Pusan National University, and Sungkyunkwan University Demonstrate Subatomic Ferroelectric Domains Inspired by Mineral Structures] A research team led by Prof. Si-Young Choi from the Department of Materials Science and Engineering and the Department of Semiconductor Engineering at POSTECH (Pohang University of Science and Technology) has discovered ferroelectric phenomena occurring at a subatomic scale in the natural mineral Brownmillerite*1 , in collaboration with Prof. Jae-Kwang Lee’s team from Pusan National University as well as Prof. Woo-Seok Choi's team from Sungkyunkwan University. The research was published on May 20 in Nature Materials. Electronic devices store data in memory units called 'domains,' whose minimum size limits the density of stored information. However, ferroelectric-based memory has been facing challenges in minimizing domain size due to the collective nature of atomic vibrations. The research team found inspiration to overcome these limitations in nature. They focused on Brownmillerite, a naturally occurring mineral characterized by its unique alternating layers of tetrahedral (FeO4) and octahedral (FeO6) iron-oxygen structures, resembling a sandwich with alternating layers of bread and ham. Strikingly, Brownmillerite exhibits a special phenomenon known as 'phonon decoupling*2 .' Phonons represent atomic vibrations; normally, when atoms vibrate, nearby atoms are also influenced, due to collective vibrations. However, in Brownmillerite, when the tetrahedral layers vibrate, the adjacent octahedral layers remain mostly unaffected. This unique property enables the selective formation of domains within the tetrahedral layers when an electric field is applied. This phenomenon was confirmed in various types of Brownmillerite, such as thin films of SrFeO2.5 and CaFeO2.5. and a single crystalline CaFeO2.5. Their experiments demonstrated that the electric field influenced only the tetrahedral layers, altering the atomic positions while leaving the octahedral layers unchanged. The team further demonstrated the practicality of this phenomenon by successfully developing ferroelectric capacitors and thin-film transistor devices based on this structure. If commercialized, this technology is expected to enable the development of memory devices that are tens of times smaller and faster than current models. Consequently, the storage capacity and processing speed of smartphones and computers could be significantly improved, accelerating advancements in high-speed data processing technologies such as artificial intelligence (AI) and autonomous vehicles. Prof. Si-Young Choi of POSTECH remarked, “This study exemplifies how wisdom derived from nature can provide critical solutions to technological limitations. Unlocking the secrets of still-unexplained natural phenomena could further enhance the applicability of various advanced technologies.” This research was supported by the Core Facility Center Project (Materials Imaging and Analysis Center), the Researcher Program of the Ministry of Science and ICT, the Nano and Materials Technology Development Program, and the Next-generation Intelligent Semiconductor Technology Development Program. DOI: https://doi.org/10.1038/s41563-025-02233-7 1. Brownmillerite: An oxide with the chemical formula ABO₂.₅, characterized by a crystal structure in which oxygen tetrahedra and octahedra are alternately stacked. 2. Phonon decoupling : A phenomenon in which lattice vibrations within a crystal structure can move independently without interfering with each other.