Scientists Have Developed a Powder Model for 3D Printing Magnets

Nanocrystalline materials can serve as raw materials for 3D printing permanent magnets.
Photo Credit: Oksana Meleshchuk

Scientists of the Ural Federal University have described the processes of magnetization reversal of nanocrystalline alloys used as raw materials for 3D printing of magnetic systems. The description of the research and the results have been published in the Journal of Magnetism and Magnetic Materials. 

Permanent magnets are products made of hard magnetic materials capable of maintaining the state of magnetization for a long time. They are used as autonomous sources of magnetic field to convert mechanical energy into electrical energy and vice versa. Applications of permanent magnets include robotics, magnetic resonance imaging, production of wind generators, electric motors, mobile phones, high-quality speakers, home appliances, and hard disk drives.

The use of permanent magnets makes it possible to reduce the dimensions of some products and increase their efficiency. The development of power engineering and robotics, miniaturization of high-tech devices, and electric and hybrid vehicles require an annual increase in the production of permanent magnets and at the same time improvement of their magnetic properties. At the same time, one of the most important tasks in the production of permanent magnets is to increase their coercivity (the value of the external magnetic field strength required for complete demagnetization of a ferro- or ferrimagnetic substance).

Chance twists ordered carbon nanotubes into ‘tornado films’

Jacques Doumani is a graduate student in applied physics at Rice and the lead author of a study published in Nature Communications.
Photo Credit: Jeff Fitlow/Rice University

Chiral materials interact with light in very precise ways that are useful for building better displays, sensors and more powerful devices. However, engineering properties such as chirality reliably at scale is still a significant challenge in nanotechnology.

Rice University scientists in the lab of Junichiro Kono have developed two ways of making wafer-scale synthetic chiral carbon nanotube (CNT) assemblies starting from achiral mixtures. According to a study in Nature Communications, the resulting “tornado” and “twisted-and-stacked” thin films can control ellipticity ⎯ a property of polarized light ⎯ to a level and in a range of the spectrum that was previously largely beyond reach.

“These approaches have granted us the ability to deliberately and consistently introduce chirality to materials that, until now, did not exhibit this property on a macroscopic scale,” said Jacques Doumani, a graduate student in applied physics at Rice and the lead author of the study. “Our methods yield thin, flexible films with tunable chiral properties.”

High-performance Magnesium-Air Primary Battery with Nitrogen-doped Nanoporous Graphene as Air Electrodes

Magnesium (Mg) is one of the most readily available battery materials. Using brine as the electrolyte with carbon-based cathodes, Mg-air primary batteries can be constructed at a low cost. Researchers at the University of Tsukuba employed nanoporous graphene electrodes and a solid electrolyte to obtain a battery with performance equivalent or even superior to those of platinum electrode-based batteries.
Image Credit:  © Yoshikazu Ito

In pursuit of a carbon-neutral society, advancement of battery technology becomes imperative. Primary batteries, though nonrechargeable, hold promise as power sources for sensors and disaster scenarios because of their cost-effective production and voltage stability. However, most of these batteries employ expensive metal electrodes, such as lithium electrodes, necessitating exploration of alternative electrode materials.

Using carbon-based materials for the cathode, magnesium (Mg) for the anode, oxygen from the atmosphere as the cathode active material, and brine for the electrolyte, Mg-air primary batteries can be constructed using inexpensive and abundant materials. Theoretically, these batteries are expected to match lithium-air batteries with regard to performance. However, they do not perform well in terms of battery capacity and operational stability.

Drug-filled nanocapsule helps make immunotherapy more effective in mice

Image illustrates the effect of lactate oxidase (LOx) nanocapsules (depicted in orange) within solid tumors. By reducing lactate concentrations and generating hydrogen peroxide in the tumor microenvironment, these nanocapsules promote the infiltration and activation of T cells (depicted in blue and green).
Image Credit: Courtesy of the Jing Wen laboratory.

UCLA researchers have developed a new treatment method using a tiny nanocapsule to help boost the immune response, making it easier for the immune system to fight and kill solid tumors.

The investigators found the approach, described in the journal Science Translational Medicine, increased the number and activity of immune cells that attack the cancer, making cancer immunotherapies work better.

“Cancer immunotherapy has reshaped the landscape of cancer treatment,” said senior author of the study Jing Wen, assistant adjunct professor of microbiology, immunology, & molecular genetics at the David Geffen School of Medicine at UCLA and a scientist at the UCLA Jonsson Comprehensive Cancer Center. “However, not all patients with solid tumors respond well to immunotherapy, and the reason seems to be related to the way the cancer cells affect their surroundings.”

Cancer cells produce a lot of lactate, Wen explained, which creates an environment around the solid tumor that makes it difficult for the immune system to work effectively against the cancer.

Super-efficient laser light-induced detection of cancer cell-derived nanoparticles

Schematic diagram of light-induced assembly of extracellular vesicles (EV)   Using laser irradiation, the researchers managed to directly detect nanoscale EVs in a cell supernatant within minutes.   
Illustration Credit: Takuya Iida, Osaka Metropolitan University

Can particles as minuscule as viruses be detected accurately within a mere 5 minutes? Osaka Metropolitan University scientists say yes, with their innovative method for ultrafast and ultrasensitive quantitative measurement of biological nanoparticles, opening doors for early diagnosis of a broad range of diseases. 

Nanoscale extracellular vesicles (EVs) including exosomes, with diameters of 50–150 nm, play essential roles in intercellular communication and have garnered attention as biomarkers for various diseases and drug delivery capsules. Consequently, the rapid and sensitive detection of nanoscale EVs from trace samples is of vital importance for early diagnosis of intractable diseases such as cancer and Alzheimer's disease. However, the extraction of nanoscale EVs from cell culture media previously required a complex and time-consuming process involving ultracentrifugation.

Understanding bacterial motors may lead to more efficient nanomachine motors

The FliG protein in the "bacterial motor"
Illustration Credit: Atsushi Hijikata, Yohei Miyanoiri, Osaka University

A research group led by Professor Emeritus Michio Homma (he, him) and Professor Seiji Kojima (he, him) of the Graduate School of Science at Nagoya University, in collaboration with Osaka University and Nagahama Institute of Bio-Science and Technology, have made new insights into how locomotion occurs in bacteria. The group identified the FliG molecule in the flagellar layer, the ‘motor’ of bacteria, and revealed its role in the organism. These findings suggest ways in which future engineers could build nanomachines with full control over their movements. They published the study in iScience. 

As nanomachines become smaller, researchers are taking inspiration from microscopic organisms for ways to make them move and operate. In particular, the flagellar motor can rotate clockwise and counterclockwise at a speed of 20,000 rpm. If scaled up, it would be comparable to a Formula One engine with an energy conversion efficiency of almost 100% and the capacity to change its rotation direction instantly at high speeds. Should engineers be able to develop a device like a flagellar motor, it would radically increase the maneuverability and efficiency of nanomachines. 

Stacking Order and Strain Boosts Second-Harmonic Generation with 2D Janus Hetero-bilayers

Second-harmonic generation of 2D Janus MoSSe/MoS2 hetero-bilayers is optimized by stacking order and strain.
Image Credit: ©Nguyen Tuan Hung et al.

A group of researchers from Tohoku University, Massachusetts Institute of Technology (MIT), Rice University, Hanoi University of Science and Technology, Zhejiang University, and Oak Ridge National Laboratory have proposed a new mechanism to enhance short-wavelength light (100-300 nm) by second harmonic generation (SHG) in a two-dimensional (2D), thin material composed entirely of commonplace elements.

Since UV light with SHG plays an important role in semiconductor lithography equipment and medical applications that do not use fluorescent materials, this discovery has important implications for existing industries and all optical applications.

Functional architecture that builds itself

Nanocomponents as organic dyes or nanoparticles bind to the surface of the chips and form 3D molecular architectures.
Photo Credit: Christoph Hohmann / LMU

Imagine hundreds of Lego bricks coming together and spontaneously forming, say, a house. And then, before you know it, the whole play mat is filled with hundreds of houses. Although this does not work in real life, it can be accomplished effortlessly at the molecular level – provided the conditions are right. Nature has mastered the principle of self-organization by exploiting intermolecular forces and electrostatic attraction. In this way, complex 3D structures with a specific function are seemingly formed by magic. Light-harvesting complexes for photosynthesis or hydrophobic, self-cleaning lotus leaves are two examples. “It’s exactly this principle of self-assembly that we’re adapting for our purposes and using to develop methods for functionalizing surfaces on the nanometer scale. To do this, we combine lithographic methods with DNA origami, enabling us to construct ordered 3D nanostructures,” explains Dr. Irina Martynenko, a postdoctoral researcher in physics professor Tim Liedl’s research group at LMU. The research team has now published its results in the journal Nature Nanotechnology. “The fields of application for nano- and micro-structured substrates are extremely diverse, ranging from microchips and biosensors to solar cells. This makes the principle of self-assembly so advantageous,” observes Martynenko.

Energy Harvesting Via Vibrations: Researchers develop highly durable and efficient device

The principle, structural design, and application of carbon fiber-reinforced polymer-enhanced piezoelectric nanocomposite materials.
Illustration Credit: ©Tohoku University

An international research group has engineered a new energy-generating device by combining piezoelectric composites with carbon fiber-reinforced polymer (CFRP), a commonly used material that is both light and strong. The new device transforms vibrations from the surrounding environment into electricity, providing an efficient and reliable means for self-powered sensors.

Details of the group's research were published in the journal Nano Energy.

Energy harvesting involves converting energy from the environment into usable electrical energy and is something crucial for ensuring a sustainable future.

"Everyday items, from fridges to street lamps, are connected to the internet as part of the Internet of Things (IoT), and many of them are equipped with sensors that collect data," says Fumio Narita, co-author of the study and professor at Tohoku University's Graduate School of Environmental Studies. "But these IoT devices need power to function, which is challenging if they are in remote places, or if there are lots of them."

High-performing alloy developed to help harness fusion energy

The research team demonstrated that minor additions of hafnium into the WTaCrV high entropy alloy lead to higher radiation resistance.
Photo credit: Courtesy of Los Alamos National Laboratory

A newly developed tungsten-based alloy that performs well in extreme environments similar to those in fusion reactor prototypes may help harness fusion energy.

“The new alloy shows promising resistance to irradiation resistance and stability under the high temperatures and extreme irradiation environments used to represent a fusion-reactor environment,” said Osman El Atwani, a staff scientist at Los Alamos National Laboratory. “The development of this alloy, and the agreement between modeling and experimentation that it represents, points the way toward the development of further useful alloys, an essential step in making fusion power generation more robust, cost-effective, economically predictable and attractive to investors.”

As fusion energy concepts move closer to the real world, solving the materials challenge is imperative. The encouraging results indicate that a design paradigm, as described by El Atwani and his collaborators, and high entropy alloys may be ready to play their role in harnessing the promise of fusion.

El Atwani was the principal investigator for the project, which involved several national and international institutions. Their results were published in Nature Communications.

Nanomaterials: glass printed sintered-free in 3D

The new process can be used to create a wide variety of quartz glass structures on a nanometer scale.
Full Size Image
 Image Credit: Dr. Jens Bauer, KIT

Process developed at KIT manages with relatively low temperatures and enables high resolutions for applications in optics and semiconductor technology - publication in science

Nanometer-fine structures made of quartz glass, which can be printed directly on semiconductor chips, are produced by a process developed at the Karlsruhe Institute of Technology (KIT). A hybrid organic-inorganic polymer resin serves as the starting material for the 3D printing of silicon dioxide. Since the process does not require sintering, the temperatures required for this are significantly lower. At the same time, a higher resolution enables nanophotonics with visible light. The research team reports in the journal Science.

Printing quartz glass consisting of pure silicon dioxide in micro and nanometer-fine structures opens up new possibilities for many applications in optics, photonics and semiconductor technology. So far, however, techniques based on traditional sintering have dominated. The temperatures required for sintering silicon dioxide nanoparticles are above 1,100 degrees Celsius - far too hot for direct separation on semiconductor chips. A research team led by Dr. Jens Bauer from the KIT's Institute for Nanotechnology (INT) has now developed a new process for producing transparent quartz glass with high resolution and excellent mechanical properties at significantly lower temperatures.

A lung injury therapy derived from adult skin cells

Natalia Higuita-Castro, seated, with the core team that worked in the lab on this study during the COVID-19 lockdown (L-R): Maria Angelica Rincon-Benavides, a PhD student in the Biophysics Graduate Program, and biomedical engineering postdoctoral fellows Ana Salazar-Puerta and Tatiana Cuellar-Gaviria.
Photo Credit: Matt Schutte

Therapeutic nanocarriers engineered from adult skin cells can curb inflammation and tissue injury in damaged mouse lungs, new research shows, hinting at the promise of a treatment for lungs severely injured by infection or trauma.

Researchers conducted experiments in cell cultures and mice to demonstrate the therapeutic potential of these nanoparticles, which are extracellular vesicles similar to the ones circulating in humans’ bloodstream and biological fluids that carry messages between cells. 

The hope is that a drop of solution containing these nanocarriers, delivered to the lungs via the nose, could treat acute respiratory distress syndrome (ARDS), one of the most frequent causes of respiratory failure that leads to putting patients on a ventilator. In ARDS, inflammation spiraling out of control in the lungs so seriously burdens the immune system that immune cells are unable to tend to the initial cause of the damage. 

Imaging agents light up two cancer biomarkers at once to give more complete picture of tumor

Researcher Indrajit Srivastava holds solutions of nanoparticles that can target two cancer biomarkers, giving off two distinct signals when lit by one fluorescent wavelength.  This could give surgeons a more complete picture of a tumor and guide operating-room decisions. In the background is a microscopic scan of a tissue sample. 
Photo Credit: Fred Zwicky

Cancer surgeons may soon have a more complete view of tumors during surgery thanks to new imaging agents that can illuminate multiple biomarkers at once, University of Illinois Urbana-Champaign researchers report. The fluorescent nanoparticles, wrapped in the membranes of red blood cells, target tumors better than current clinically approved dyes and can emit two distinct signals in response to just one beam of surgical light, a feature that could help doctors distinguish tumor borders and identify metastatic cancers. 

The imaging agents can be combined with bioinspired cameras, which the researchers previously developed for real-time diagnosis during surgery, said research group leader Viktor Gruev, an Illinois professor of electrical and computer engineering. In a new study in the journal ACS Nano, the researchers demonstrated their new dual-signal nanoparticles in tumor phantoms – 3D models that mimic the features of tumors and their surroundings – and in live mice. 

“If you want to find all the cancer, imaging one biomarker is not enough. It could miss some tumors. If you introduce a second or a third biomarker, the likelihood of removing all cancer cells increases, and the likelihood of a better outcome for the patients increases.” said Gruev, who also is a professor in the Carle Illinois College of Medicine. “Multiple-targeted drugs and imaging agents are a recent trend, and our group is driving the trend hard because we have the camera technology that can image multiple signals at once.”

With new experimental method, researchers probe spin structure in 2D materials for first time

In the study, researchers describe what they believe to be the first measurement showing direct interaction between electrons spinning in a 2D material and photons coming from microwave radiation.
 Graphic Credit: Jia Li, an assistant professor of physics at Brown.

For two decades, physicists have tried to directly manipulate the spin of electrons in 2D materials like graphene. Doing so could spark key advances in the burgeoning world of 2D electronics, a field where super-fast, small and flexible electronic devices carry out computations based on quantum mechanics.

Standing in the way is that the typical way in which scientists measure the spin of electrons — an essential behavior that gives everything in the physical universe its structure — usually doesn’t work in 2D materials. This makes it incredibly difficult to fully understand the materials and propel forward technological advances based on them. But a team of scientists led by Brown University researchers believe they now have a way around this longstanding challenge. They describe their solution in a new study published in Nature Physics.

In the study, the team — which also include scientists from the Center for Integrated Nanotechnologies at Sandia National Laboratories, and the University of Innsbruck — describe what they believe to be the first measurement showing direct interaction between electrons spinning in a 2D material and photons coming from microwave radiation. Called a coupling, the absorption of microwave photons by electrons establishes a novel experimental technique for directly studying the properties of how electrons spin in these 2D quantum materials — one that could serve as a foundation for developing computational and communicational technologies based on those materials, according to the researchers.

NUS scientists develop a novel light-field sensor for 3D scene construction with unprecedented angular resolution

Prof Liu Xiaogang (right) and Dr Yi Luying from the NUS Department of Chemistry capturing a 3D image of a model using the light-field sensor.
Photo Credit: Courtesy of National University of Singapore

Color-encoding technique for light-field imaging has potential applications in fields such as autonomous driving, virtual reality and biological imaging

A research team from the National University of Singapore (NUS) Faculty of Science, led by Professor Liu Xiaogang from the Department of Chemistry, has developed a 3D imaging sensor that has an extremely high angular resolution, which is the capacity of an optical instrument to distinguish points of an object separated by a small angular distance, of 0.0018o. This innovative sensor operates on a unique angle-to-color conversion principle, allowing it to detect 3D light fields across the X-ray to visible light spectrum.  

A light field encompasses the combined intensity and direction of light rays, which the human eyes can process to precisely detect the spatial relationship between objects. Traditional light sensing technologies, however, are less effective. Most cameras, for instance, can only produce two-dimensional images, which is adequate for regular photography but insufficient for more advanced applications, including virtual reality, self-driving cars, and biological imaging. These applications require precise 3D scene construction of a particular space.

Researchers develop technique for rapid detection of neurodegenerative diseases like Parkinson’s and CWD

Illustration Credit: Sang-Hyun Oh Research Group, University of Minnesota

University of Minnesota researchers have developed a groundbreaking new diagnostic technique that will allow for faster and more accurate detection of neurodegenerative diseases. The method will likely open a door for earlier treatment and mitigation of various diseases that affect humans, such as Alzheimer's and Parkinson's, and similar diseases that affect animals, such as chronic wasting disease (CWD).

Their new study is published in Nano Letters.

“This research mainly focuses on chronic wasting disease in deer, but ultimately our goal is to expand the technology for a broad spectrum of neurodegenerative diseases, Alzheimer’s and Parkinson’s being the two main targets,” said Sang-Hyun Oh, senior co-author of the paper and a professor in the College of Science and Engineering. “Our vision is to develop ultra-sensitive, powerful diagnostic techniques for a variety of neurodegenerative diseases so that we can detect biomarkers early on, perhaps allowing more time for the deployment of therapeutic agents that can slow down the disease progression. We want to help improve the lives of millions of people affected by neurodegenerative diseases.”

A simple paper test could offer early cancer diagnosis

MIT engineers have designed a new nanoparticle sensor that can enable cancer diagnosis with a simple urine test. The nanoparticles (blue) carry DNA barcodes (zigzag lines) that can be cleaved by cancer-associated proteases in the body (pac-man shapes). Once cleaved, the DNA barcodes can be detected in a urine sample.
Illustration Credit: Courtesy of the researchers. Edited by MIT News

MIT engineers have designed a new nanoparticle sensor that could enable early diagnosis of cancer with a simple urine test. The sensors, which can detect many different cancerous proteins, could also be used to distinguish the type of a tumor or how it is responding to treatment.

The nanoparticles are designed so that when they encounter a tumor, they shed short sequences of DNA that are excreted in the urine. Analyzing these DNA “barcodes” can reveal distinguishing features of a particular patient’s tumor. The researchers designed their test so that it can be performed using a strip of paper, similar to an at-home Covid test, which they hope could make it affordable and accessible to as many patients as possible.

“We are trying to innovate in a context of making technology available to low- and middle-resource settings. Putting this diagnostic on paper is part of our goal of democratizing diagnostics and creating inexpensive technologies that can give you a fast answer at the point of care,” says Sangeeta Bhatia, the John and Dorothy Wilson Professor of Health Sciences and Technology and of Electrical Engineering and Computer Science at MIT and a member of MIT’s Koch Institute for Integrative Cancer Research and Institute for Medical Engineering and Science.

Researchers discover new self-assembled crystal structures

 Conceptual image showcasing several interaction potential shapes, represented by stems, that will lead to the self-assembly of new low-coordinated crystal structures, represented by flowers. 
Image Credit: Hillary Pan

Using a targeted computational approach, researchers in the Department of Materials Science and Engineering at Cornell have found more than 20 new self-assembled crystal structures, none of which had been observed previously.

The research, published in the journal ACS Nano under the title “Targeted Discovery of Low-Coordinated Crystal Structures via Tunable Particle Interactions,” is authored by Ph.D. student Hillary Pan and her advisor Julia Dshemuchadse, assistant professor of materials science and engineering.

“Essentially we were trying to figure out what kinds of new crystal structure configurations we can self-assemble in simulation,” Pan said. “The most exciting thing was that we found new structures that weren’t previously listed in any crystal structure database; these particles are actually assembling into something that nobody had ever seen before.”

The team conducted a targeted search for previously unknown low-coordinated assemblies within a vast parameter space spanned by particles interacting via isotropic pair potentials, the paper states. “Low-coordinated structures have anisotropic local environments, meaning that the geometries are highly directional, so it’s incredible that we’re able to see such a variety of these types of structures using purely non-directional interactions,” said Pan.

Scientists Develop Effective Silicon Surface Processing Technology

The technology will be useful in the creation of solar cells, as well as in biomedicine, chemistry, and IT.
 Photo Credit: Ilya Safarov

A team of scientists from Ekaterinburg (UrFU), Moscow, and St. Petersburg has developed a new technology for processing silicon wafers. It is a hybrid chemical and laser texturing, in which the wafer is treated with a femtosecond laser beam after chemical exposure to various reagents. Pre-chemical etching allows for five times faster laser treatment and improves light absorption over a broad spectral range. The technology will be useful in making solar cells. It could also be used in biomedicine for highly sensitive sensors for DNA analysis and detection of viruses and bacteria. It is also used in chemistry and in information and communication technologies. A description of the new technology has been published in the journal Materials.

"Currently, the formation of light-absorbing micro-reliefs on the surface of silicon wafers is achieved by a chemical process that is relatively inexpensive and used on an industrial scale. However, after chemical treatment, the wafers have a significant reflection coefficient, which reduces the efficiency of solar cells. An alternative method is laser treatment of the wafers. It reduces the reflection, but requires a significant amount of time using a femtosecond laser. Our proposed laser treatment after chemical etching reduces the processing time by a factor of five. At the same time, the reflection coefficient of wafers processed by the hybrid method is 7-10% lower than after chemical treatment," says Vladimir Shur, Director of the Ural Multiple Access Center "Modern Nanotechnologies" of the UrFU.

New blue light technique could enable advances in understanding nanoscale technologies

Photo Credit: Courtesy of Brown University

With a new microscopy technique that uses blue light to measure electrons in semiconductors and other nanoscale materials, a team of Brown University researchers is opening a new realm of possibilities in the study of these critical components, which can help power devices like mobile phones and laptops.

The findings are a first in nanoscale imaging and provide a workaround to a longstanding problem that has greatly limited the study of key phenomena in a wide variety of materials that could one day lead to more energy-efficient semiconductors and electronics. The work was published in Light: Science & Applications.

“There is a lot of interest these days in studying materials with nanoscale resolution using optics,” said Daniel Mittleman, a professor in Brown’s School of Engineering and author of the paper describing the work. “As the wavelength gets shorter, this becomes a lot harder to implement. As a result, nobody had ever done it with blue light until now.”