#postech

Scientists revive legendary golden sea silk using Korean pen shell byssus

A luxurious fiber once reserved exclusively for emperors in ancient times has been brought back to life by Korean researchers. A team led by Professor Dong Soo Hwang and Professor Jimin Choi 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 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.

Twisted oxide crystals show how atomic patterns alone can trap or repel electrons

It has been revealed that simply twisting and stacking two layers of oxide crystals can allow the atomic arrangement itself to control the behavior of electrons. Much like the new patterns that emerge when two meshes are overlapped and rotated, a twisted oxide interface forms specific atomic configurations that act as an "invisible fence," either trapping or repelling electrons. A research team led by Prof. Si-Young Choi in the Department of Materials Science and Engineering and the Department of Semiconductor Engineering at POSTECH (Pohang University of Science and Technology), in collaboration with Prof. Chang-Beom Eom and postdoctoral researcher Kyoungjun Lee at the University of Wisconsin–Madison, and Prof. Ryo Ishikawa at the University of Tokyo, has elucidated the mechanism underlying this phenomenon in twisted oxide interfaces formed at specific rotation angles. This work was published as a cover article in the journal ACS Nano.

Prussian Blue finally transformed into octahedral structure after 300 years

For the first time in more than three centuries, Prussian Blue—long confined to its rigid cubic shape—has been transformed into an octahedral structure. A research team has successfully synthesized this new morphology by replacing water with a specialized solvent, glycerol, during the crystal growth process. Their findings were recently published online in Advanced Functional Materials. Accidentally discovered around the 1700s, Prussian Blue possesses a hollow three-dimensional framework that allows ions to move in and out with ease. These unique properties have enabled its use across diverse fields, from sodium-ion battery electrodes to radioactive cesium removal, catalysis, and environmental remediation. However, until now, its morphology had been limited. When synthesized in water, the reaction proceeds too quickly, making it difficult to control particle growth and producing only cubic particles. This constraint has prevented scientists from exploring shape-dependent properties or unlocking new applications.

A research team at POSTECH (Pohang University of Science and Technology), led by Professor Hyoung Seop Kim from the Department of Materials Science and Engineering, Graduate Institute of Ferrous Technology, and Department of Mechanical Engineering, has developed a new alloy that maintains its strength and ductility across extreme temperatures ranging from -196 °C to 600 °C. The findings, which have drawn attention from the aerospace and automotive industries, were published in the international journal Materials Research Letters. Most metals used in everyday life are sensitive to temperature changes -- metal doorknobs feel icy in winter and scalding in summer. Consequently, conventional metal materials are typically optimized for performance within a narrow temperature range, limiting their effectiveness in environments with dramatic temperature fluctuations

Body-compatible electrode developed: Rigid on insertion, soft once inside

A research team at POSTECH (Pohang University of Science and Technology) has developed a novel electrode that the human body does not reject. This advance addresses a fundamental limitation of current wearable technology and is attracting significant attention from the academic community. A team led by Professor Geunbae Lim of the Department of Mechanical Engineering, together with Dr. Jungho Lee and Dr. Gaeun Yun, in collaboration with Professor Sung-Min Park and Professor Chulhong Kim, has developed a "Dermal Bioelectrode (Dermal Electronics)" that minimizes pain and inflammation while enabling stably biosignal measurement unaffected by external environmental factors. The study has been published in Advanced Materials.

A research team led by Professor Hyung Joon Cha from POSTECH's Department of Chemical Engineering and Graduate School of Convergence Science and Technology with a specialization in Medical Science, along with Dr. Jinyoung Yun and Integrated Program student Hyun Taek Woo from the Department of Chemical Engineering, has developed an innovative injectable adhesive hydrogel for bone regeneration. This hydrogel utilizes harmless visible light to simultaneously achieve cross-linking and mineralization without the need for bone grafts. The groundbreaking research was recently published online in Biomaterials. Bone defects, which arise from various causes such as trauma, infection, and congenital abnormalities, are becoming increasingly common in aging societies. Conventional treatments often involve bone grafts combined with serum or bioadhesives to fill the defect. However, existing injectable hydrogels face challenges such as difficulty in maintaining their shape within the body and limited adhesive strength. Moreover, traditional methods using bone grafts with adhesive materials often fail to achieve simultaneous "bone regeneration" and "adhesion."

Shape memory polymers with nanotips help solve micro-LED chip transfer problem

A research team at Pohang University of Science and Technology (POSTECH), 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 journal Nature Communications, and the team was 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, U.S.).