Nanostructures of virtually any possible shape can now be made using a combination of techniques developed to exploit the unique properties of so-called perovskites. The group based in the Netherlands, developed a pulsed laser deposition technique to create patterns in ultra thin layers, one atomic layer at a time. The perovskites’ crystal structure is undamaged by this soft lithography technique, maintaining electrical conductivity.
Drawn relentlessly by their electrical charges, lithium ions in a battery surge from anode to cathode and back again. Yet, no one really understands what goes on at the atomic scale as lithium ion batteries are used and recharged. Using transmission electron microscopy, researchers are now glimpsing what can happen to anodes as lithium ions work their way into them. The “atomic shuffling” these ions perform leads to rapid anode failure.
A Duke Univ. team has found that nanoparticles called single-walled carbon nanotubes accumulate quickly in the bottom sediments of an experimental wetland setting, an action they say could indirectly damage the aquatic food chain. According to the research, the risk to humans ingesting the particles through drinking water is slight, but aquatic food chains might be harmed by molecules "piggybacking" on the carbon nanoparticles.
Cancer vaccines have recently emerged as a promising approach for killing tumor cells before they spread. But so far, most clinical candidates haven’t worked that well. Now, scientists have developed a new way to deliver vaccines that successfully stifled tumor growth when tested in laboratory mice. And the key is in the vaccine’s unique stealthy nanoparticles.
Ice contains many atoms and molecules trapped inside its structure. A team of Univ. of Chicago and Loyola Univ. researchers has discovered a new mechanism they call "stable energetic embedding" of atoms and molecules within ice. This mechanism explains how some molecules, such as CF4, or "carbon tetrafluoride", interact with and become embedded beneath ice surfaces.
Despite being outlawed in 2012 in the U.S., the synthetic drugs known as "bath salts" are still readily available in some retail shops, on the Internet and on the streets. To help law enforcement, scientists are developing low-cost, disposable, mercury-free electrodes that could be the basis for the first portable, on-site testing device for identifying the drugs.
Thermal considerations are rapidly becoming one of the most serious design constraints in microelectronics, especially on submicron scale lengths. A study by researchers from the Univ. of Illinois at Urbana-Champaign has shown that standard thermal models will lead to the wrong answer in a 3-D heat-transfer problem if the dimensions of the heating element are on the order of one micron or smaller.
Inspired by a desire to help wounded soldiers, an international team has created a paint-on, see-through, “smart” bandage that glows to indicate a wound’s tissue oxygenation concentration. Because oxygen plays a critical role in healing, mapping these levels in severe wounds and burns can help to greatly improve the success of surgeries to restore limbs and physical functions.
Researchers in the Netherlands can now, for the first time, remotely control a miniature light source at timescales of 200 trillionths of a second. Physicists have developed a way of remotely controlling the nanoscale light sources at an extremely short timescale. These light sources are needed to be able to transmit quantum information.
Graphene quantum dots created at Rice Univ. grab onto graphene platelets like barnacles attach themselves to the hull of a boat. But these dots enhance the properties of the mothership, making them better than platinum catalysts for certain reactions within fuel cells.
Electrical engineers in Germany have demonstrated a new kind of building block for digital integrated circuits. Their experiments show that future computer chips could be based on 3-D arrangements of nanometer-scale magnets instead of transistors. In a 3-D stack of nanomagnets, the researchers have implemented a so-called “majority” logic gate, which could serve as a programmable switch in a digital circuit.
Michael Grätzel’s laboratory in Switzerland is producing hydrogen fuel from sunlight and water. By combining a pair of solar cells made with a mineral called perovskite and low cost electrodes, scientists have obtained a 12.3% conversion efficiency from solar energy to hydrogen, a record using earth-abundant materials as opposed to rare metals.
Mathematicians from Brown Univ. have introduced a new element of uncertainty into an equation used to describe the behavior of fluid flows. Ironically, allowing uncertainty into a mathematical equation that models fluid flows makes the equation much more capable of correctly reflecting the natural world, including the formation, strength, and position of air masses and fronts in the atmosphere.
A Univ. of Texas at Arlington research team says recently identified radiation detection properties of a light-emitting nanostructure built in their lab could open doors for homeland security and medical advances. In a paper to be published in Optics Letters, the team describes a new method to fabricate transparent nanoscintillators by heating nanoparticles composed of lanthanum, yttrium and oxygen until a transparent ceramic is formed.
Droplets are simple spheres of fluid, not normally considered capable of doing anything on their own. But now researchers have made droplets of alcohol move through water, even moving through complex mazes. The droplets can be led to certain targets, using a surprisingly simple impetus. In the future, such moving droplets may deliver medicines, moving entire chemistries to targets.
In a rare case of having their cake and eating it too, scientists from NIST and other institutions have developed a toolset that allows them to explore the complex interior of tiny, multi-layered batteries they devised. It provides insight into the batteries’ performance without destroying them, which results in both a useful probe for scientists and a potential power source for micromachines.
Researchers from the Univ. of Texas at Dallas have created technology that could be the first step toward wearable computers with self-contained power sources or, more immediately, a smartphone that doesn’t die after a few hours of heavy use. This technology taps into the power of a single electron to control energy consumption inside transistors, which are at the core of most modern electronic systems.
A novel x-ray technique used at the U.S. Department of Energy’s Advanced Photon Source has revealed surprising dynamics in the nanomechanics of operating batteries and suggests a way to mitigate battery failures by minimizing the generation of elastic energy. The method could open a path to wider use of these batteries in conjunction with renewable energy sources.
A little change in temperature makes a big difference for growing a new generation of hybrid atomic-layer structures, according to scientists. Rice Univ. scientists led the first single-step growth of self-assembled hybrid layers made of two elements that can either be side by side and one-atom thick or stacked atop each other. The structure’s final form can be tuned by changing the growth temperature.
The key to creating a material that would be ideal for converting solar energy to heat is tuning the material’s spectrum of absorption just right: It should absorb virtually all wavelengths of light that reach Earth’s surface from the sun—but not much of the rest of the spectrum, since that would increase the energy that is reradiated by the material, and thus lost to the conversion process.
Scanning electron microscopes can determine chemical compositions with the help of energy dispersive spectrometers. However, lighter elements like carbon emit secondary fluorescence in an energy range insufficiently resolved by these instruments. Physicists have developed a potential solution to this problem by adding reflection zone plate optics to a specialized spectrometer that delivers high resolution from 50 to 1,120 eV.
Confined photons have many potential applications, such as efficient miniature lasers, on-chip information storage, or tiny sensors on pharmaceuticals. Making a structure that can capture photons is difficult, but scientists in the Netherlands have recently devised a new type of resonant cavity inside a photonic crystal that imprisons light in all three dimensions.
Electricity and magnetism rule our digital world. Semiconductors process electrical information, while magnetic materials enable long-term data storage. A Univ. of Pittsburgh research team has discovered a way to fuse these two distinct properties in a single material, paving the way for new ultrahigh density storage and computing architectures.
The excessive atmospheric carbon dioxide that is driving global climate change could be harnessed into a renewable energy technology that would be a win for both the environment and the economy. That is the lure of artificial photosynthesis in which the electrochemical reduction of carbon dioxide is used to produce clean, green and sustainable fuels.
Concrete can be better and more environmentally friendly by paying attention to its atomic structure, according to researchers at Rice Univ., the Massachusetts Institute of Technology and Marseille Univ. The international team of scientists has created computational models to help concrete manufacturers fine-tune mixes for general applications.