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Category: nanotechnology – Page 141

What goes on inside planets like Neptune and Uranus? To find out, an international team headed by the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), the University of Rostock and France’s École Polytechnique conducted a novel experiment. They fired a laser at a thin film of simple PET plastic and investigated what happened using intensive laser flashes. One result was that the researchers were able to confirm their earlier thesis that it really does rain diamonds inside the ice giants at the periphery of our solar system. And another was that this method could establish a new way of producing nanodiamonds, which are needed, for example, for highly-sensitive quantum sensors. The group has presented its findings in the journal Science Advances.

The conditions in the interior of icy giant planets like Neptune and Uranus are extreme: temperatures reach several thousand degrees Celsius, and the pressure is millions of times greater than in the Earth’s atmosphere. Nonetheless, states like this can be simulated briefly in the lab: powerful laser flashes hit a film-like material sample, heat it up to 6,000 degrees Celsius for the blink of an eye and generate a shock wave that compresses the material for a few nanoseconds to a million times the atmospheric pressure.

“Up to now, we used hydrocarbon films for these kinds of experiment,” explains Dominik Kraus, physicist at HZDR and professor at the University of Rostock. “And we discovered that this produced tiny diamonds, known as nanodiamonds.”

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Breakthroughs in modern microelectronics depend on understanding and manipulating the movement of electrons in metal. Reducing the thickness of metal sheets to the order of nanometers can enable exquisite control over how the metal’s electrons move. By doing so, one can impart properties that aren’t seen in bulk metals, such as ultrafast conduction of electricity. Now, researchers from Osaka University and collaborating partners have synthesized a novel class of nanostructured superlattices. This study enables an unusually high degree of control over the movement of electrons within metal semiconductors, which promises to enhance the functionality of everyday technologies.

Precisely tuning the architecture of metal nanosheets, and thus facilitating advanced microelectronic functionalities, remains an ongoing line of work worldwide. In fact, several Nobel prizes have been awarded on this topic. Researchers conventionally synthesize nanostructured superlattices—regularly alternating layers of metals, sandwiched together—from materials of the same dimension; for example, sandwiched 2D sheets. A key aspect of the present researchers’ work is its facile fabrication of hetero-dimensional superlattices; for example, 1D nanoparticle chains sandwiched within 2D nanosheets.

“Nanoscale hetero-dimensional superlattices are typically challenging to prepare, but can exhibit valuable physical properties, such as anisotropic electrical conductivity,” explains Yung-Chang Lin, senior author. “We developed a versatile means of preparing such structures, and in so doing we will inspire synthesis of a wide range of custom superstructures.”

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The new research provides a more complete picture of how diamond rain forms on other planets.

Researchers have discovered that “diamond rain,” unique precipitation that has long been speculated to occur on icy giant planets, may occur more frequently than previously believed.

To learn more about the circumstances on the icy giant planets Neptune and Uranus, a group of researchers from Germany and France has created an intriguing experiment, according to an article published by Physic.org on Friday.

A team of researchers have discovered that “diamond rain,” unique precipitation that has long been speculated to occur on ice giant planets, may occur more frequently than previously believed.

Continue reading “Scientists create nanodiamonds from plastic bottles” | >

“We don’t need any energy input, and it bubbles hydrogen like crazy. I’ve never seen anything like it,” said UCSC Professor Scott Oliver, describing a new aluminum-gallium nanoparticle powder that generates H2 when placed in water – even seawater.

Aluminum by itself rapidly oxidizes in water, stripping the O out of H2O and releasing hydrogen as a byproduct. This is a short-lived reaction though, because in most cases the metal quickly attains a microscopically thin coating of aluminum oxide that seals it off and puts an end to the fun.

But chemistry researchers at UC Santa Cruz say they’ve found a cost-effective way to keep the ball rolling. Gallium has long been known to remove the aluminum oxide coating and keep the aluminum in contact with water to continue the reaction, but previous research had found that aluminum-heavy combinations had a limited effect.

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The skin is one of the largest and most accessible organs in the human body, but penetrating its deep layers for medicinal and cosmetic treatments still eludes science.

Although there are some remedies—such as nicotine patches to stop smoking—administered through the skin, this method of treatment is rare since the particles that penetrate must be no larger than 100 nanometers. Creating effective tools using such tiny particles is a great challenge. Because the particles are so small and difficult to see, it is equally challenging to determine their exact location inside the body—information necessary to ensure that they reach intended target tissue. Today such information is obtained through invasive, often painful, biopsies.

A novel approach, developed by researchers at Bar-Ilan University in Israel, provides an innovative solution to overcoming both of these challenges. Combining techniques in nanotechnology and optics, they produced tiny (nanometric) diamond particles so small that they are capable of penetrating skin to deliver medicinal and cosmetic remedies. In addition, they created a safe, laser-based optical method that quantifies nanodiamond penetration into the various layers of the skin and determines their location and concentration within body tissue in a non-invasive manner—eliminating the need for a biopsy.

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Composite particles with submicron sizes can be produced by irradiating a suspension of nanoparticles with a laser beam. Violent physical and chemical processes take place during irradiation, many of which have been poorly understood to date. Recently completed experiments, carried out at the Institute of Nuclear Physics of the Polish Academy of Sciences in Cracow, have shed new light on some of these puzzles.

When a strikes agglomerates of nanoparticles suspended in a colloid, events occur that are as dramatic as they are useful. The tremendous increase in temperature leads to the melting together of nanoparticles into a composite particle. A thin layer of liquid next to the heated material rapidly transforms into vapor, and whole sequences of chemical reactions take place under that change in fractions of a second. Using this method, called laser melting, scientists from the Institute of Nuclear Physics of the Polish Academy of Sciences (IFJ PAN) in Cracow not only produced new nanocomposites, but also described some of the poorly understood processes responsible for their formation.

“The laser melting process itself, consisting of irradiating particles of material in suspension with unfocused laser light, has been known for years. It is mainly used for the production of single component materials. We, as one of only two research teams in the world, are trying to use this technique to produce composite submicron particles. In this area, the field is still in its infancy, there are still many unknowns, hence our joy that some puzzles that perplexed us have just been unraveled,” says Dr. Żaneta Świątkowska-Warkocka, a professor at IFJ PAN, the co-author of a scientific article just published in the journal Scientific Reports.

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Are you ready to put mini robots in your mouth?

Do you get lazy about brushing your teeth? Well, soon microbots could do the whole thing for you. A multidisciplinary team at the University of Pennsylvania has created a novel automated way to perform brushing and flossing through robotics, according to a press release published by the institution last month.

The development could be particularly useful for those who lack the manual dexterity to clean their teeth effectively themselves.

A shapeshifting robotic microswarm may one day act as a toothbrush, rinse, and dental floss in one.

Continue reading “Shapeshifting Microrobots Can Brush and Floss Teeth” | >

Solar cell manufacturing just became easier, more efficient, and less costly. A team of researchers at DOE’s Lawrence Berkeley National Laboratory (Berkeley Lab), in collaboration with UC Berkeley, has discovered a unique material that can be used as a simpler approach to solar cell manufacturing, the team reported.

This material is a crystalline solar material with a built-in electric field — also known as “ferroelectricity” — that was reported earlier this year in the journal Science Advances.

Light microscopy image of nanowires, 100 to 1,000 nanometers in diameter, grown from cesium germanium tribromide (CGB) on a mica substrate. The CGB nanowires are samples of a new lead-free halide perovskite solar material that is also ferroelectric. (Credit: Peidong Yang and Ye Zhang/Berkeley Lab)

Solar panels, also known as photovoltaics, rely on semiconductor devices, or solar cells, to convert energy from the sun into electricity.

Continue reading “Scientists Grow Lead-Free Solar Material With a Built-In Switch” | >

Inside a living cell, proteins and other molecules are often tightly packed together. These dense clusters can be difficult to image because the fluorescent labels used to make them visible can’t wedge themselves in between the molecules.

MIT researchers have now developed a novel way to overcome this limitation and make those “invisible” molecules visible. Their technique allows them to “de-crowd” the molecules by expanding a cell or before labeling the molecules, which makes the molecules more accessible to fluorescent tags.

This method, which builds on a widely used technique known as previously developed at MIT, should allow scientists to visualize molecules and cellular structures that have never been seen before.

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