. Scientific Frontline: Nanotechnology
Showing posts with label Nanotechnology. Show all posts
Showing posts with label Nanotechnology. Show all posts

Thursday, February 15, 2024

Innovative materials to combat bacteria

Three bacteria from the ESKAPE group: Staphylococcus aureus (yellow), Pseudomonas aeruginosa (short thick blue rods) and Escherichia coli (long blue rods).
Image Credit: © UNIGE

While crucial to biotechnology, bacteria can also cause severe disease, exacerbated by their increasing resistance to antibiotics. This duality between economic benefits and infectious risks underlines the importance of finding ways to control their development. A team at the University of Geneva (UNIGE) is currently developing a new generation of bactericidal alloys, with a wide range of industrial applications. They could be used to treat the contact surfaces responsible for their transmission. The project, which is supported by Innosuisse, will take 18 months to complete.

Resistance to antimicrobial drugs - such as antibiotics and antivirals - is a global public health issue. According to the World Health Organization (WHO), it is currently responsible for 700,000 deaths a year worldwide. If no action is taken, the number of deaths will rise to 10 million a year by 2050, with dramatic consequences for public health and the economy.

To promote and guide research in this field, the WHO has published a list of pathogens that should be targeted as a matter of priority, because they are particularly threatening to human health. The list includes Staphylococcus aureus and E. coli bacteria, which are associated with the most common hospital-acquired infections, as well as salmonella. Contaminated contact surfaces (utensils, handles, stair railings) play a fundamental role in their transmission.

Monday, February 12, 2024

Artificial cartilage with the help of 3D printing

The spheroids in which living cells are grown, can be assembled into almost any shape.
Image Credit: Technische Universität Wien

A new approach to producing artificial tissue has been developed at TU Wien: Cells are grown in microstructures created in a 3D printer.

Is it possible to grow tissue in the laboratory, for example to replace injured cartilage? At TU Wien (Vienna), an important step has now been taken towards creating replacement tissue in the lab - using a technique that differs significantly from other methods used around the world.

A special high-resolution 3D printing process is used to create tiny, porous spheres made of biocompatible and degradable plastic, which are then colonized with cells. These spheroids can then be arranged in any geometry, and the cells of the different units combine seamlessly to form a uniform, living tissue. Cartilage tissue, with which the concept has now been demonstrated at TU Wien, was previously considered particularly challenging in this respect.

Thursday, December 21, 2023

New brain-like transistor mimics human intelligence

An artistic interpretation of brain-like computing.
Illustration Credit: Xiaodong Yan/Northwestern University

Taking inspiration from the human brain, researchers have developed a new synaptic transistor capable of higher-level thinking.

Designed by researchers at Northwestern University, Boston College and the Massachusetts Institute of Technology (MIT), the device simultaneously processes and stores information just like the human brain. In new experiments, the researchers demonstrated that the transistor goes beyond simple machine-learning tasks to categorize data and is capable of performing associative learning.

Although previous studies have leveraged similar strategies to develop brain-like computing devices, those transistors cannot function outside cryogenic temperatures. The new device, by contrast, is stable at room temperatures. It also operates at fast speeds, consumes very little energy and retains stored information even when power is removed, making it ideal for real-world applications.

“The brain has a fundamentally different architecture than a digital computer,” said Northwestern’s Mark C. Hersam, who co-led the research. “In a digital computer, data moves back and forth between a microprocessor and memory, which consumes a lot of energy and creates a bottleneck when attempting to perform multiple tasks at the same time. On the other hand, in the brain, memory and information processing are co-located and fully integrated, resulting in orders of magnitude higher energy efficiency. Our synaptic transistor similarly achieves concurrent memory and information processing functionality to more faithfully mimic the brain.”

Monday, December 18, 2023

For this emergent class of materials, ‘solutions are the problem’

Alec Ajnsztajn (left) and Jeremy Daum
Photo Credit: Gustavo Raskosky/Rice University

Rice University materials scientists developed a fast, low-cost, scalable method to make covalent organic frameworks (COFs), a class of crystalline polymers whose tunable molecular structure, large surface area and porosity could be useful in energy applications, semiconductor devices, sensors, filtration systems and drug delivery.

“What makes these structures so special is that they are polymers but they arrange themselves in an ordered, repeating structure that makes it a crystal,” said Jeremy Daum, a Rice doctoral student and lead author of a study published in ACS Nano. “These structures look a bit like chicken wire ⎯ they’re hexagonal lattices that repeat themselves on a two-dimensional plane, and then they stack on top of themselves, and that’s how you get a layered 2D material.”

Alec Ajnsztajn, a Rice doctoral alumnus and the study’s other lead author, said the synthesis technique makes it possible to produce ordered 2D crystalline COFs in record time using vapor deposition.

“A lot of times when you make COFs through solution processing, there’s no alignment on the film,” Ajnsztajn said. “This synthesis technique allows us to control the sheet orientation, ensuring that pores are aligned, which is what you want if you’re creating a membrane.”

Friday, December 15, 2023

Ultrafast lasers map electrons 'going ballistic' in graphene, with implications for next-gen electronic devices

Ultrafast Laser Lab.
Photo Credit: KU Marketing Communications

Research appearing in ACS Nano, a premier journal on nanoscience and nanotechnology, reveals the ballistic movement of electrons in graphene in real time.

The observations, made at the University of Kansas’ Ultrafast Laser Lab, could lead to breakthroughs in governing electrons in semiconductors, fundamental components in most information and energy technology.

“Generally, electron movement is interrupted by collisions with other particles in solids,” said lead author Ryan Scott, a doctoral student in KU’s Department of Physics & Astronomy. “This is similar to someone running in a ballroom full of dancers. These collisions are rather frequent — about 10 to 100 billion times per second. They slow down the electrons, cause energy loss and generate unwanted heat. Without collisions, an electron would move uninterrupted within a solid, similar to cars on a freeway or ballistic missiles through air. We refer to this as ‘ballistic transport.’”

Scott performed the lab experiments under the mentorship of Hui Zhao, professor of physics & astronomy at KU. They were joined in the work by former KU doctoral student Pavel Valencia-Acuna, now a postdoctoral researcher at the Northwest Pacific National Laboratory.

Zhao said electronic devices utilizing ballistic transport could potentially be faster, more powerful and more energy efficient.

Wednesday, December 13, 2023

The 'one-pot' nanosheet method catalyzing a green energy revolution

Illustration Credit: Minoru Osada

A research group from the Institute for Future Materials and Systems at Nagoya University in Japan has developed a new “one-pot” method to make nanosheets using less rare metals. Their discovery should allow for the energy-making process to be more eco-friendly. The journal ACS Nano published the study.

Producing clean energy is important because it helps reduce global warming and contributes to building a carbon-neutral society. A potential source of clean energy uses hydrogen catalysts, such as palladium (Pd). Industries use Pd in electrolysis to separate water into hydrogen and oxygen. Afterward, the hydrogen in fuel cells is used to create electricity. The only byproduct is water. 

Pd is commonly used in a spherical ‘nanoparticle’ form for catalyst use. However, a flatter, thinner surface would use fewer precious metals and increase the available surface area for the reaction.

Minoru Osada at Nagoya University and his research group have developed a new way to make Pd nanosheets. They named it the "one-pot method" because it can be done in a single glass bottle. The resulting sheets were so thin (1~2 nm) that they can be compared to the size of a single molecule or DNA strand.

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).

Monday, December 11, 2023

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.”

Tuesday, October 17, 2023

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.

Thursday, October 12, 2023

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.

Friday, October 6, 2023

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.

Wednesday, September 27, 2023

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. 

Tuesday, September 26, 2023

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.

Monday, September 25, 2023

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.

Thursday, June 15, 2023

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."

Tuesday, June 13, 2023

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.

Wednesday, June 7, 2023

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.

Tuesday, June 6, 2023

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. 

Monday, June 5, 2023

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.”

Thursday, May 11, 2023

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.

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