A novel crystalline material is readily grown from low-melting-temperature mixtures—a result that points toward a new route to above-room-temperature ferromagnets.
Researchers at Purdue University have discovered new waves with picometer-scale spatial variations of electromagnetic fields which can propagate in semiconductors like silicon. The research team, led by Dr. Zubin Jacob, Elmore Associate Professor of Electrical and Computer Engineering and Department of Physics and Astronomy (courtesy) published their findings in APS Physics Review Applied in a paper titled, “Picophotonics: Anomalous Atomistic Waves in Silicon.”
“The word microscopic has its origins in the length scale of a micron which is a million times smaller than a meter. Our work is for light matter interaction within the picoscopic regime which is far smaller, where the discrete arrangement of atomic lattices changes light’s properties in surprising ways.” says Jacob.
These intriguing findings demonstrate that natural media host a variety of rich light-matter interaction phenomena at the atomistic level. The use of picophotonic waves in semiconducting materials may lead researchers to design new, functional optical devices, allowing for applications in quantum technologies.
Advances in computing power over the decades have come thanks in part to our ability to make smaller and smaller transistors, a building block of electronic devices, but we are nearing the limit of the silicon materials typically used. A new technique for creating 2D oxide materials may pave the way for future high-speed electronics, according to an international team of scientists.
“One way we can make our transistors, our electronic devices, work faster is to shrink the distance electrons have to travel between point A and B,” said Joshua Robinson, professor of materials science and engineering at Penn State. “You can only go so far with 3D materials like silicon—once you shrink it down to a nanometer, its properties change. So there’s been a massive push looking at new materials, one of which are 2D materials.”
The team, led by Furkan Turker, graduate student in the Department of Materials Sciences, used a technique called confinement hetroepitaxy, or CHet, to create 2D oxides, materials with special properties that can serve as an atomically thin insulating layer between layers of electrically conducting materials.
Prof. Wang Hui, together with Prof. Lin Wenchu and associate Prof. Qian Junchao from the Hefei Institutes of Physical Science (HFIPS) of the Chinese Academy of Sciences, have recently reported a near infrared (NIR)-II-responsive carbon-coated iron oxide nanocluster that was guided by magnetic resonance imaging and capable of combined photothermal and chemodynamic therapy (CDT), for synergistic cancer treatment.
The results were published in SCIENCE CHINA Materials.
As a promising treatment strategy, CDT has become a hot spot in cancer research due to its simple operation and low side effects. The basic principle of CDT is that the nanozymes activate the intracellular Fenton reaction, leading to the over-production of hydroxyl radicals, which are toxic to cancer cells. Magnetite nanocrystals are widely used as Fenton reagents due to their non-invasive imaging ability and good biocompatibility. However, the ferromagnetic behavior and easy oxidization of magnetite nanocrystals lead to colloidal instability as nanozymes and limit the imaging-guided cancer therapy in practical applications.
Physicists at the University of Wisconsin-Madison have directly measured the fluid-like flow of electrons in graphene at nanometer resolution for the first time. The results appear in the journal Science today.
Graphene, an atom-thick sheet of carbon arranged in a honeycomb pattern, is an especially pure electrical conductor, making it an ideal material to study electron flow with very low resistance. Here, researchers intentionally add impurities at known distances, and find that electron flow changes from gas-like to fluid-like as the temperature rises.
“All conductive materials contain impurities and imperfections that block electron flow, which causes resistance. Historically, people have taken a low-resolution approach to identifying where resistance comes from,” says Zach Krebs, a physics graduate student at UW-Madison and co-lead author of the study. “In this study, we image how charge flows around an impurity and actually see how that impurity blocks current and causes resistance, which is something that hasn’t been done before to distinguish gas-like and fluid-like electron flow.”
A well-known mineral is once again the center of attention thanks to applications in electronics: the Vienna University of Technology shows that mica still possesses some surprises.
At first glance, mica appears to be quite ordinary: it is a prevalent mineral found in materials like granite and has undergone extensive examination from geological, chemical, and technical standpoints.
At first, it may seem that there’s nothing groundbreaking that can be uncovered about such a commonplace material. However, a team from the Vienna University of Technology has recently published a study in Nature Communications.
Vibrations are the main drivers of a mysterious process in which a liquid flow generates an electric current in the solid below it.
Liquid flowing over a conducting surface is known to produce electric currents, but the mechanism behind this effect has been unclear. New experiments with a single liquid drop dragged over a graphene surface demonstrate that viscous forces at the liquid–solid interface create vibrations, or phonons, in the graphene sheet that drag electrons in the direction of the flow [1]. The researchers verified this “phonon wind” interpretation by observing multiple liquids and by testing graphene surfaces with and without wrinkles. The results could lead to highly sensitive flow sensors or to devices that can harvest electricity from flows.
Researchers have found that water flowing over a material—in particular, carbon nanotubes or graphene—can generate electric currents in the solid. The effect appears in carbon materials because the surfaces are atomically flat and thus allow the liquid to flow largely unobstructed at the liquid–solid boundary, explains Alessandro Siria from the École Normale Supérieure in France. Several models have been proposed to explain the flow-induced currents, often involving charges within the liquid acting on the electrons in the solid. However, experimental uncertainties have prevented researchers from determining which model is best.
Molecules from mucus can be used to produce synthetic bone graft material and help with the healing of larger bone loss, a new study found.
Researchers at KTH Royal Institute of Technology report the development of a bioactive gel which they say could replace the clinical gold standard of autografting, in which lost bone is replaced with healthy bone taken from another part of the patient’s body.
Hongji Yan, a researcher at KTH Royal Institute of Technology, says the gel contains mucins, molecules which were derived from cow mucus. The mucins are processed into gels which are combined with monetite granules, a commonly-used synthetic bone graft material. The synthetic gel can be injected to the site of the bone loss.
Generative AI is a catch-all term describing programs that use artificial intelligence to create new material from complex queries, such as “write a poem about monkeys in the style of Robert Frost” or “make an image of pandas draped over living room furniture.”
While AI more generally refers to software programs that can make themselves better by “learning” from new data, and which have been used behind the scenes in all kinds of software for years, generative AI is a fresh consumer-facing spin on the concept.
About 1,000 people from all over the world, including AI researchers and content marketers, attended Tuesday’s Gen AI Conference, which was organized by startup Jasper. It was a lavish affair, held at Pier 27 on the Embarcadero, overlooking San Francisco Bay.
Some researchers are driven by the quest to improve a specific product, like a battery or a semiconductor. Others are motivated by tackling questions faced by a given industry. Rob Macfarlane, MIT’s Paul M. Cook Associate Professor in Materials Science and Engineering, is driven by a more fundamental desire.
“I like to make things,” Macfarlane says. “I want to make materials that can be functional and useful, and I want to do so by figuring out the basic principles that go into making new structures at many different size ranges.” (Image: Adam Glanzman)
