Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: materials – Page 5

Metamaterials: Shaping The Future Of Optics And Electromagnetism

Metamaterials are artificial materials engineered to exhibit unique properties not found in naturally occurring materials, including negative refractive index, perfect absorption of electromagnetic radiation, and tunable optical properties. Researchers have been exploring the use of metamaterials in various applications, including optics, electromagnetism, and acoustics. One area where metamaterials are being explored is in sensing and imaging applications, such as creating ultra-compact optical devices like beam splitters and lenses.

The first practical demonstration of a metamaterial was achieved in 2000 by David Smith and his team at the University of California, San Diego. They created a composite material consisting of copper strips and dielectric materials, which exhibited a negative refractive index at microwave frequencies. This breakthrough sparked widespread interest in the field, and soon researchers began exploring various applications of metamaterials.

One of the key areas of research has been in the development of optical metamaterials. In 2005, a team led by Xiang Zhang at the University of California, Berkeley demonstrated the creation of an optical metamaterial with negative refractive index. They achieved this by using a fishnet-like structure composed of silver and dielectric materials. This work paved the way for further research into optical metamaterials and their potential applications in fields such as optics and photonics.

Metamaterials have also been explored for their potential use in electromagnetic cloaking devices. In 2006, a team led by David Smith demonstrated the creation of a metamaterial cloak that could bend light around an object, effectively making it invisible. This work was based on earlier theoretical proposals by John Pendry and his colleagues.

“No One Had Any Idea This Existed” — Astronomers Discover Hidden River of Gas Flowing to the Milky Way’s Heart

Newly identified Midpoint cloud reveals rare insight into star formation and the movement of galactic material toward the center of the Milky Way. A group of astronomers from around the world has identified a vast cloud of gas and dust in an underexplored part of the Milky Way. This structure, cl

Massive magnets are on the move: Repurposing electromagnets for research

Plan a route, grab some snacks, and fuel up. Engineers and scientists have been sending massive magnets from U.S. Department of Energy (DOE) national labs on cross-country road trips.

Magnets are at the heart of many scientific instruments at DOE’s Brookhaven National Laboratory. They are not like typical refrigerator magnets, which apply a relatively weak and uniform force to . These electromagnets are often incredibly large and powerful, with variable fields that can be controlled by changing the electric current that runs through them.

One of their applications is to apply magnetic force to subatomic particles. For example, the Relativistic Heavy Ion Collider (RHIC) is made of superconducting electromagnets that steer and focus particle beams as they circulate through the accelerator at nearly the speed of light.

How sputtering could drive the adoption of high-performance ScAlN-based transistors

Gallium nitride (GaN)-based high electron mobility transistors (HEMTs) are a type of field-effect transistors (FETs) designed to operate at very high frequencies with low noise. As such, they have been widely applied in high-power and high-frequency applications, like high-speed wireless communications, power switching devices, and power amplifiers.

HEMTs utilize a heterojunction, which is a junction between two different semiconductor materials, typically GaN and aluminum GaN (AlGaN). This junction creates a narrow region called the two-dimensional electron gas (2DEG), where electrons have very high mobility, resulting in excellent high-frequency performance.

Scandium aluminum nitride (ScAlN) has attracted significant attention as a novel barrier material that can further enhance the performance of GaN HEMTs. It exhibits large polarization, which increases electron densities in the 2DEG. Additionally, its ferroelectric nature makes it suitable for use as a ferroelectric gate material in ferroelectric HEMTs.

A Scalable Artificial Neuron Based on Ultrathin Two-Dimensional Titanium OxideClick to copy article linkArticle link copied!

A spiking neural network consists of artificial synapses and neurons and may realize human-level intelligence. Unlike the widely reported artificial synapses, the fabrication of large-scale artificial neurons with good performance is still challenging due to the lack of a suitable material system and integration method. Here, we report an ultrathin (less than10 nm) and inch-size two-dimensional (2D) oxide-based artificial neuron system produced by a controllable assembly of solution-processed 2D monolayer TiOx nanosheets. Artificial neuron devices based on such 2D TiOx films show a high on/off ratio of 109 and a volatile resistance switching phenomenon. The devices can not only emulate the leaky integrate-and-fire activity but also self-recover without additional circuits for sensing and reset. Moreover, the artificial neuron arrays are fabricated and exhibited good uniformity, indicating their large-area integration potential. Our results offer a strategy for fabricating large-scale and ultrathin 2D material-based artificial neurons and 2D spiking neural networks.

Sunlight-activated material turns PFAS in water into harmless fluoride

Researchers at the University of Adelaide have developed a sunlight-activated material that can degrade per- and polyfluoroalkyl substances (PFAS) in water, breaking down the pollutant into harmless components, including fluoride. The work is published in the journal Small.

Programmable Soft Materials: A Leap Forward in Energy Absorption and Shape-Shifting Design

Researchers from Lawrence Livermore National Laboratory (LLNL), in collaboration with Harvard University, Caltech, Sandia National Laboratories, and Oregon State University, have unveiled a groundbreaking innovation in materials science: a programmable soft material capable of bending, bouncing, and absorbing energy on demand. This new material, described in the journal Advanced Materials, could pave the way for next-generation protective gear, aerospace structures, and adaptive robotic systems.

👉 Read the original article on Phys.org

Programmable soft material bends, bounces and absorbs energy on demand

Scientists at Lawrence Livermore National Laboratory (LLNL) and their collaborators have created a new class of programmable soft materials that can absorb impacts like never before, while also changing shape when heated.

The research—which includes collaborators from Harvard University, the California Institute of Technology (Caltech), Sandia National Laboratories and Oregon State University—opens the door to smarter, lighter and more resilient materials that respond to the world around them. The research is published in the journal Advanced Materials.

Built from liquid crystal elastomers (LCEs)—rubbery polymers that shift in response to heat, light or stress—the team 3D-printed the materials into carefully engineered lattice structures. These lattices can be designed to absorb energy, stiffen, soften or even change shape, depending on their architecture and environmental conditions.

Protecting the biomolecules with simple peptides

In biology, cells often respond to stress by creating protective compartments through a process known as phase separation. These compartments stabilize vulnerable proteins and can dissolve again when conditions improve. The research team applied this principle to design adaptable peptide-based materials that mimic this process—offering a simple and effective alternative to conventional methods for biomolecular stabilization, which often require complex formulations and cold-chain logistics.

Key findings from the study include:

A new study reveals that extremely simple peptides can mimic a biological process that protects sensitive proteins from environmental stress. The findings, published in Nature Materials, offer a promising new approach to stabilizing biomolecules like vaccines and therapeutic proteins—potentially without the need for refrigeration.

The interdisciplinary study demonstrates how short peptides—just three amino acids long—can undergo liquid–liquid phase separation through a drying process that enables the peptides to encapsulate proteins, protect them, and release them intact upon rehydration.

“Inspired by how organisms like tardigrades survive extreme dehydration, we asked whether we could replicate nature’s strategy using minimal synthetic materials,” said the atuhor. “To our surprise, we found that simple tripeptides could form dynamic, reversible structures that protect proteins under stress. This opens up new possibilities for protein preservation.”

/* */