Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: materials

Ancient hominins selected basalt sources for specific tools nearly 800,000 years ago, study reveals

A new study finds that ancient hominins nearly 800,000 years ago deliberately selected specific basalt sources for different stages of tool production rather than simply using whatever stone was available nearby. By tracing the geochemical “fingerprints” of stone tools to both exposed and now-buried basalt flows, the researchers demonstrated that these hominins possessed detailed environmental knowledge, advanced planning abilities, and long-term technological traditions that were maintained and repeated across generations.

A new study published in Scientific Reports provides new insights into the technological behavior and raw material procurement strategies of early Middle Pleistocene hominins at the Acheulian site of Gesher Benot Ya’aqov (GBY). The study uses geochemical analyses of basalt artifacts and nearby basalt sources to trace where the raw material used for tool production came from and to reconstruct how early hominins selected stone within a landscape that has changed dramatically over time. The research was carried out by Dr. Tzahi Golan and Dr. Yoav Ben Dor of the Geological Survey of Israel, and Prof. Naama Goren-Inbar of the Hebrew University of Jerusalem.

GBY, dated to about 780,000 years ago, preserves repeated occupations of Acheulian hominins along the shores of paleo-Lake Hula. Excavations directed by Prof. Goren-Inbar revealed a rich archaeological record, including stone tools made of flint, limestone and basalt, as well as evidence of fire use, plant exploitation, animal processing and fish consumption.

Achiral crystal reveals Raman optical activity through ferroaxial order

Raman optical activity, long thought to require chiral molecules or magnetic order, has been demonstrated in an achiral, nonmagnetic crystal by researchers at the Institute of Science Tokyo. The effect arises through ferroaxial order, a coordinated rotation of atoms within the lattice, and is detected using circularly polarized Raman spectroscopy. The findings show that optically inactive materials can also display chirality-like optical responses and expand the scope of optical techniques for discovering new materials.

In nature, molecules can be divided into two categories based on their symmetry: chiral and achiral. Chiral molecules are not identical to their mirror images, much like left and right hands. Achiral molecules, by contrast, are identical to their mirror images and therefore do not possess a definite handedness.

Light offers a way to distinguish between these two types. When light interacts with a chiral molecule, the response depends on its handedness. For example, chiral molecules absorb left-and right-circularly polarized light to different extents, a phenomenon known as circular dichroism. They also scatter these two types of light with different intensities, an effect called Raman optical activity (ROA), which is widely used to identify chirality. ROA has long been associated only with chiral molecules or with materials that have magnetic order, where inversion or time-reversal symmetry is broken.

PLA Block Polymers: Versatile Materials for a Sustainable Future

Block polymers present an almost endless realm of possibilities to develop functional materials for myriad applications. The established self-assembly of block polymers allows researchers to access properties that are inaccessible in homopolymers. However, there is a need to develop more sustainable options than the current commodity block polymers. Derived from renewable resources and industrially compostable, poly(lactide) (PLA) is at the forefront of technological advancements in sustainable block polymers. Its material properties including high stiffness, relatively high glass transition temperature, and semicrystallinity in isotactic versions lend themselves to many applications, and its ease of synthesis provides a well-established platform for developing high-performance materials. This Perspective highlights recent advancements associated with PLA-containing block polymers, including their syntheses, mesostructural considerations, and mechanical properties, from resilient elastomers to tough plastics. We also give our perspective on the subfield of PLA block polymers, our outlook on the future, and our assessment of exciting developments yet to come.

Injectable hydrogel relieves osteoarthritis pain and repairs cartilage in preclinical tests

For millions of people living with osteoarthritis, daily life can involve a frustrating cycle of pain and stiffness. While current treatments like over-the-counter medications or steroid injections can temporarily dull the ache, they do not stop the joint from deteriorating. A Yale study published in the journal Bioactive Materials found that the medication lacosamide acts as a highly effective, dual-purpose treatment that relieves joint pain and reverses cartilage damage in osteoarthritis, especially when a specialized hydrogel delivers the drug directly into the joint.

No Free Lunch for Sound Waves

Sound wave scattering can be increased in one frequency range only by reducing scattering in another range, according to experiments—a discovery relevant for acoustic engineering.

Acoustic metamaterials allow blocking, absorbing, or redirecting waves in ways not possible with conventional materials. Now researchers have shown that all such structures face a previously unrecognized constraint: The total acoustic scattering is fixed, so that boosting scattering in one frequency band necessarily depletes it elsewhere [1]. This general restriction provides a new way of thinking about how acoustic performance can be optimized, which could guide the design of broadband sound-control devices, from noise barriers to acoustic cloaks.

By building structures into materials on length scales smaller than the wavelength of sound, researchers can create artificial resonant elements that interact strongly with acoustic waves. Such structures can produce effects that are difficult or impossible to achieve otherwise—for example, strong sound attenuation through thin material layers. Such advances have led to new techniques for lightweight soundproofing and sound steering.

Physicists discover attractive forces between molecular condensates may cause running off

Inside cells, certain functions are carried out by locally adjusting molecular composition. This condensation of material results in the formation of dense droplets that can dynamically rearrange. Because of this, interactions between such dense regions determine the shaping of condensates. Scientists from the Department of Living Matter Physics at MPI-DS recently developed a model that can describe such phase separation dynamics based solely on attraction. The work is published in the journal Physical Review Letters.

“It’s natural to think that a system with only attractive forces would form one large, stationary condensate,” explained Jacopo Romano, first author of the study.

“However, instead we observed an unexpected emergent property of chasing dynamics resulting in movement and propulsion,” he said.

Ultrathin nanotubes reach 1 nanometer, opening path to smaller electronics

Researchers in Japan have created some of the world’s smallest semiconducting nanotubes, structures 100,000 times thinner than a human hair. By growing molybdenum disulfide inside protective tubes of boron nitride, the researchers, including those from the University of Tokyo, produced highly uniform tubes just 1 nanometer wide, a scale at which it’s difficult to make stable nanotube structures. The work confirms decades-old theoretical predictions about how these ultrafine materials behave and could also provide a new route toward miniaturized electronic devices.

The research is published in the journal Science.

A few years ago, carbon nanotubes were attracting a lot of press attention. But there’s a new contender in the ring, and it offers some advantages over its carbon counterpart that could tempt engineers to design products around it.

How ‘asymmetric alloying’ is creating the next generation of luminescent materials

Metal cluster molecules are discrete compounds containing multiple metal atoms held together by metal–metal and metal–ligand bonding. They serve as excellent candidates for catalysts, biosensors, and even for drug development. Developing atomic-level molecular editing methods for such metal clusters remains an important challenge and represents a promising strategy for expanding their structural and functional diversity. Such approaches can enable structure-specific properties, high near-infrared (NIR) photoluminescence quantum yields, and unique reactivities and electronic structures.

Alloying is a powerful method for achieving this goal. In this regard, a key challenge is asymmetric alloying, which introduces asymmetry into the metal cluster by selectively placing heterometal atoms at nonequivalent sites, desymmetrizing the cluster and therefore imparting chirality-associated functionality.

Moreover, highly selective asymmetric synthesis methods for heterometallic clusters are expected to contribute significantly to the development of chiroptical materials. However, methods capable of achieving such controlled asymmetric synthesis have rarely been reported.

Photoexcitation flips 2D moiré devices from metals to insulators in ultrafast test

Quantum materials, materials with properties that are governed by the laws of quantum mechanics describing many-body interactions, have proved promising for the development of various advanced technologies. Many of these materials undergo so-called phase transitions, switching between different physical states that alter how electrons flow through them.

Some previous studies have demonstrated the transition from insulating states to metallic states in quantum materials, via a process called photoexcitation (i.e., the excitation of electrons using light). Yet the opposite transition, from metallic to insulating states, has so far proved difficult to realize using light alone.

Researchers at Columbia University, in collaboration with UC Riverside, recently demonstrated an ultrafast photo-induced metal-to-insulator transition in two-dimensional (2D) moiré heterostructures, quantum materials consisting of 2D layers stacked on top of each other, with a slight misalignment between them.

New solar desalination breakthrough makes fresh water without toxic brine

Scientists have developed a solar desalination system that turns seawater into drinking water without creating environmentally damaging brine. Special laser-textured metal panels use sunlight to evaporate water while automatically moving salt deposits away from the working surface, preventing clogging. The process was successfully tested with water from three oceans and can recover nearly all salts as solids. Those leftover materials could even become a source of valuable lithium for batteries.

/* */