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Engineers use kirigami to make ultrastrong, lightweight structures

Cellular solids are materials composed of many cells that have been packed together, such as in a honeycomb. The shape of those cells largely determines the material’s mechanical properties, including its stiffness or strength. Bones, for instance, are filled with a natural material that enables them to be lightweight, but stiff and strong.

Inspired by bones and other cellular solids found in nature, humans have used the same concept to develop architected materials. By changing the geometry of the unit cells that make up these materials, researchers can customize the material’s mechanical, thermal, or acoustic properties. Architected materials are used in many applications, from shock-absorbing packing foam to heat-regulating radiators.

Using , the ancient Japanese art of folding and cutting paper, MIT researchers have now manufactured a type of high-performance architected material known as a plate lattice, on a much larger scale than scientists have previously been able to achieve by additive fabrication. This technique allows them to create these structures from metal or other materials with custom shapes and specifically tailored mechanical properties.

AI platform ‘evolves’ metamaterials

With just a couple of “pieces of matter”—representations of one basic unit of a material—the new platform can create thousands of previously unknown morphologies, or structures, with the properties Amir Alavi specified.(Credit: Amir Alavi/U. Pittsburgh)

In a paper published in the journal Advanced Intelligent Systems, Amir Alavi, assistant professor of civil and environmental engineering in the University of Pittsburgh’s Swanson School of Engineering, outlines a platform for the evolution of metamaterials, synthetic materials purposefully engineered to have specific properties.

Plasmonic Metamaterials Bend Light Backwards

A thin film patterned with nanoantennas exhibits negative refraction of light, a useful feature for subwavelength imaging.

Materials that refract light the “wrong way” could be used to make optical lenses that can image objects smaller than visible wavelengths. So-called negative refraction has been demonstrated in thin films in which surface plasmons—collective charge oscillations—have been excited by a powerful laser. Now, an international team involving Purdue University, Indiana, the University of Glasgow, UK, and Imperial College London show that they can more efficiently achieve the same effect by placing an array of nanoscale antennas on the film.

Scientists trap light inside a magnet

A new study led by Vinod M. Menon and his group at the City College of New York shows that trapping light inside magnetic materials may dramatically enhance their intrinsic properties. Strong optical responses of magnets are important for the development of magnetic lasers and magneto-optical memory devices, as well as for emerging quantum transduction applications.

In their new article in Nature, Menon and his team report the properties of a layered magnet that hosts strongly bound excitons—quasiparticles with particularly strong optical interactions. Because of that, the material is capable of trapping light—all by itself.

As their experiments show, the optical responses of this material to magnetic phenomena are orders of magnitude stronger than those in typical magnets. “Since the light bounces back and forth inside the magnet, interactions are genuinely enhanced,” said Dr. Florian Dirnberger, the lead-author of the study.

Faster spin waves could make novel computing systems possible

Research is underway around the world to find alternatives to our current electronic computing technology, as great, electron-based systems have limitations. A new way of transmitting information is emerging from the field of magnonics. Instead of electron exchange, the waves generated in magnetic media could be used for transmission, but magnonics-based computing has been (too) slow to date.

Scientists at the University of Vienna have now discovered a significant new method. When the intensity is increased, the spin become shorter and faster—another step towards magnon computing. The results are published in the journal Science Advances.

Magnonics is a relatively new field of research in magnetism in which spin waves play a central role. A local disturbance in the magnetic order of a magnet can propagate as waves through a material. These waves are called spin waves, and the associated quasiparticles are called magnons. They carry information in the form of angular momentum pulses. Because of this property, they can be used as low-power data carriers in smaller and more energy-efficient computers of the future.

Chinese Scientists Develop a High-Performance Ultralong-Life Aqueous Zinc-Ion Battery

A research team has developed an advanced aqueous zinc-ion battery with an enhanced cycle lifespan using a weak magnetic field and a new VS2 material. The breakthrough addresses the challenges of zinc dendrite growth and cathode material limitations. Credit: Mao Yunjie.

A research team at the Hefei Institutes of Physical Science (HFIPS) of Chinese Academy of Sciences (CAS), led by Prof. Zhao Bangchuan, developed a high-performance aqueous zinc-ion battery with ultralong cycle lifespan in a weak magnetic field.

The findings were recently published in the journal Materials Horizons.