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Category: materials – Page 7

Rotating metamaterial units could enable long-range wave control beyond conventional limits

A Seoul National University College of Engineering research team, led by Professor Joo Hwan Oh of the Department of Mechanical Engineering, in collaboration with Dr. Myung Hwan Bae of the Korea Research Institute of Standards and Science (KRISS), has developed a new elastic metamaterial platform that enables the free design of how externally applied forces and vibrations propagate.

The team proposed a design principle that allows nonlocal metamaterials—in which forces or vibrations applied in one region can interact not only with adjacent areas but also with distant regions—to be more easily extended into diverse structural configurations.

They demonstrated experimentally that this design overcomes the longstanding issue of interference among multiple vibrations in conventional nonlocal metamaterials, enabling more precise control of the propagation and motion of elastic waves.

Chocolate syrup-like fluid stores multiple interacting memories

Animals and electronic devices aren’t the only things with memory. Materials can retain memories of past deformations in their microscopic structure. A common example is a crease in a sheet of paper that has been folded then unfolded. Understanding this type of memory could benefit the design of materials that respond to changes in their environment in predictable ways.

It can also be a source of ideas about the various types of memory studied by neuroscientists, including how short-term and long-term memories interact and influence each other. Now, researchers at Penn State have shown that two different types of material memory can coexist in a simple mixture of small particles suspended in a viscous liquid. Like long-and short-term memories, these material memories interact and compete.

A paper describing the research was recently published and highlighted as an editors’ suggestion in the journal Physical Review Letters.

Striped or checkered? Magnetic field influences competing electronic patterns in a graphene-like quantum material

In most everyday materials, such as copper, silver and silicon, the behavior of electrons is relatively predictable. In quantum materials, however, electrons can interact in complex ways, giving rise to collective electronic states with remarkable properties. Understanding how these states emerge—and, ultimately, how to control them—is one of the central challenges in quantum materials research.

Now, researchers from the Okinawa Institute of Science and Technology (OIST) and Hiroshima University have discovered that a small magnetic field switches the layered quantum material CeTe₃ between competing electronic states that appear as striped or checkerboard patterns.

Published in Nature Communications, the work reveals how magnetism can reorganize a quantum material’s entire electronic state.

Plasma design rules show how to preserve attosecond flashes for observing electrons

Researchers at Skoltech, together with a colleague from the Shanghai Institute of Optics and Fine Mechanics of the Chinese Academy of Sciences, working within the joint SIOM–Skoltech laboratory, have determined how to select the thickness and density of a plasma target so that a pulse passing through it retains its attosecond duration and high intensity. The results will help improve the design of plasma-based sources of ultraviolet and X-ray radiation used to study ultrafast processes in matter.

The work is published in Applied Physics Letters.

An attosecond is 10⁻¹⁸ of a second. Pulses of this duration can be compared to an ultrafast camera flash: They make it possible to effectively “freeze” the motion of electrons and investigate processes that cannot be resolved using longer pulses. This is important for studying atoms, molecules, solids and new materials.

Gas vapors trigger reversible phase, color change in advanced fluids

Researchers have developed a reversible, vapor-controlled system capable of toggling the physical and optical traits of advanced fluids on demand.

Led by Nagoya University and Kyoto University in Japan, the study demonstrates a method to control the optical and physical properties of materials from the molecular level to the macroscopic scale.

At the core of the development is host–guest chemistry. It is a process where two distinct molecules lock together purely through physical forces, completely avoiding permanent chemical bonds.

Fine-tuned perovskites make blue LEDs more vibrant

Over the past decade, perovskite LEDs have become increasingly vibrant and affordable to produce. With careful tweaks to their chemical composition, these crystal-based light emitters can be tuned across the visible spectrum—matching and sometimes even beating rival LED materials for producing red and green light. However, blue light has remained a holdout, keeping full-color perovskite displays out of reach.

Through new research published in Nature, a team led by Xuyong Yang at Shanghai University has found a way past this barrier, building perovskite LEDs that emit a vivid, saturated blue while also lasting longer than earlier attempts.

New super strong glue grips non-stick surfaces and wipes away easily

In a research lab at the University of Tokyo, scientists have developed a new kind of glue. It’s incredibly strong and highly stretchable, yet it washes away completely with a little alcohol.

Materials scientists have long been on the hunt for a strong glue that is also easily removable. The reason is that when it comes to adhesive strength and flexibility, there is often a trade-off. Although strong glues have an incredible grip, they are often brittle and difficult to remove without leaving residue. Weak glues, on the other hand, are easy to remove, but they aren’t strong enough for demanding jobs.

This new glue is so strong that it can even bond to nonstick surfaces like Teflon, but all it takes is a little washing with ethanol to completely remove it without leaving any residue.

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