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Category: nanotechnology – Page 5

Suppose you want to make a tiny robot to perform surgery inside a human patient. To avoid damaging healthy tissue and to squeeze into tight spots, the robot should be squishy. And manipulating the robot’s movements with magnetic fields would make sense, as tissues don’t respond to magnetism. But what material would you use for the robot’s limbs? Magnetic materials are stiff and brittle. Embedding tiny particles of them in a rubbery matrix could work, but the thinner—and therefore bendier—you make the composite material, the less it responds to a magnetic field. Heinrich Jaeger of the University of Chicago, Monica Olvera de la Cruz of Northwestern University, Illinois, and their collaborators have now overcome that obstacle by making thin, flexible sheets out of self-assembled nanoparticles of magnetite [1]. Even a modest field of 100 milliteslas can lift a sheet and bend it by 50°, they found.

At room temperature, magnetite (Fe3O4) is ferrimagnetic—that is, the magnetic moments in its two sublattices align in opposite directions but with unequal magnitudes, yielding a net magnetization. The smaller a ferrimagnet, the greater the chance that it has a single domain, and therefore the lower the temperature at which the domain’s magnetization will flip. When the sample size gets down to a few tens of nanometers, a ferrimagnet made of randomly flipping particles becomes, in effect, a paramagnet—that is, it lacks a net magnetization and is attracted by an applied magnetic field. The attraction can be strong. The discoverers of this phenomenon in 1959 dubbed it superparamagnetism [2].

The researchers realized that a sheet made from a single layer of superparamagnetic particles could serve as a viable material for the magnetic actuation of small soft robots. To create the layers, they suspended magnetite nanoparticles in droplets of water coated with an organic solvent. The solvent attracted the nanoparticles, which migrated to a droplet’s surface. The water slowly evaporated, leaving behind a layer of closely packed nanoparticles draped on the droplet’s support structure, a square copper grid. Each of the 20 × 20 µm squares supported a single sheet. As shown in the figure, some of the sheets happened to have a single unattached corner.

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In order to showcase ultra-strong artificial muscles, Ray Baughman from the University of Texas at Dallas and his colleagues built a catapult.

The scientists published their findings in the journal Science. The device contains yarns similar in diameter to human hair, spun from carbon nanotubes and soaked in paraffin wax. When a current is passed through the yarn, the wax heats up and expands. As the yarn swells, its particular helical weave causes it to shorten, and the muscle contracts. As it cools, the yarn relaxes and returns to its original length. When coiled lightly or heated to high enough temperatures, wax-free yarns behave in the same fashion.

The torque produced by the twisting and untwisting of the yarns is sufficient to power a miniature catapult. The yarn can haul 200 times the weight that a natural muscle of the same size can, and generates more torque than a large electric motor if compared by weight. Currently, the available manufacturing techniques have limited the weight of the yarn. They can make yarn that lifts up 50 grams. That doesn’t sound like much, but researchers have shown the nanotube yarns lifting loads as much as 50,000 times greater than their own weight.

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Nanobots aren’t just microscopic machines—they could come in countless shapes and sizes, each designed for a unique purpose. From medical nanobots that repair cells to swarming micro-robots that build structures at the atomic level, the future of nanotechnology is limitless. Could these tiny machines revolutionize medicine, industry, and even space exploration? #Nanotech #Nanobots #FutureTech #Science #Innovation …

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Condensation is critical for applications like power generation, water harvesting, and cooling systems. However, traditional surfaces suffer from a drop in performance under high subcooling, when the surface temperature is much lower than the surrounding vapor. This leads to water flooding and reduced heat transfer.

To tackle this long-standing challenge, researchers at National Taiwan University and National Chung Hsing University have developed a novel three-dimensional (3D) hybrid surface that significantly enhances performance and avoids flooding, even at high subcooling. The paper is published in Small Structures.

The new surface integrates short hydrophobic nanowires and hydrophilic microchannels in a structured pattern. This combination helps guide water droplets efficiently off the surface, preventing the accumulation of water that typically hampers heat transfer.

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There are a seemingly endless number of quantum states that describe quantum matter and the strange phenomena that emerge when large numbers of electrons interact. For decades, many of these states have been theoretical: mathematical and computational predictions potentially hiding among real-life materials—a zoo, as many scientists are coming to refer to it, with new “species” just waiting to be discovered and described.

In a new study published on April 3 in Nature, researchers added over a dozen states to the growing quantum zoo.

“Some of these states have never been seen before,” said lead author Xiaoyang Zhu, Howard Family Professor of Nanoscience at Columbia. “And we didn’t expect to see so many either.”

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In nature and technology, crystallization plays a pivotal role, from forming snowflakes and pharmaceuticals to creating advanced batteries and desalination membranes. Despite its importance, crystallization at the nanoscale is poorly understood, mainly because observing the process directly at this scale is exceptionally challenging. My research overcame this hurdle by employing state-of-the-art computational methods, allowing them to visualize atomic interactions in unprecedented detail.

Published in Chemical Science, my research has uncovered new details about how salt crystals form in tiny nanometer-sized spaces, which could pave the way for and improved electrochemical technologies.

This research used sophisticated enhanced by cutting-edge machine learning techniques to study how (NaCl), common table salt, crystallizes when confined between two graphene sheets separated by just a few billionths of a meter. These , known as nano-confinement, drastically alter how molecules behave compared to bulk, everyday conditions.

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Microplastics and much smaller nanoplastics enter the human body in various ways, for example through food or the air we breathe. A large proportion is excreted, but a certain amount remains in organs, blood, and other body fluids.

In the FFG bridge project Nano-VISION, which was launched two years ago together with the start-up BRAVE Analytics, a team led by Harald Fitzek from the Institute of Electron Microscopy and Nanoanalysis at Graz University of Technology (TU Graz) and an ophthalmologist from Graz addressed the question of whether nanoplastics also play a role in ophthalmology.

The project partners have now been able to develop a method for detecting and quantifying nanoplastics in transparent body fluids and determining their chemical composition. The research is published in the journal Analytical Chemistry.

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University of Queensland researchers have set a world record for solar cell efficiency with eco-friendly perovskite technology. A team led by Professor Lianzhou Wang has unveiled a tin halide perovskite (THP) solar cell capable of converting sunlight to electricity at a certified record efficiency of 16.65%. The research is published in the journal Nature Nanotechnology.

Working across UQ’s Australian Institute for Bioengineering and Nanotechnology and the School of Chemical Engineering, Professor Wang said the certified reading achieved by his lab was nearly one percentage point higher than the previous best for THP solar cells.

“It might not seem like much, but this is a giant leap in a field that is renowned for delicate and incremental progress,” Professor Wang said.

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