The time frames, in which electrons travel within atoms, are unfathomably short. For example, electrons excited by light change their quantum-mechanical location within mere attoseconds. But how fast do electrons whiz across distances corresponding to the diameter of individual atomic layers?
Today, we're surrounded by a variety of electronic devices that are moving increasingly closer to us. Many types of smart devices are readily available and convenient to use. The goal now is to make wearable electronics that are flexible, sustainable and powered by ambient renewable energy. This last goal inspired a group of researchers to explore zinc oxide as an effective material choice.
Researchers have demonstrated a new way to enhance the emission of single photons by using "hyperbolic metamaterials," a step toward creating devices in work aimed at developing quantum computers and communications technologies. Optical metamaterials harness clouds of electrons called surface plasmons to manipulate and control light.
Making cement is a centuries-old art that has yet to be perfected, according to researchers at Rice Univ. who believe it can be still more efficient. Former Rice graduate student Lu Chen and materials scientist Rouzbeh Shahsavari calculated that fine-tuning the process by which round lumps of calcium silicate called clinkers are turned into cement can save a lot of energy.
A research team led by North Carolina State Univ. has made two advances in multiferroic materials, including the ability to integrate them on a silicon chip, which will allow the development of new electronic memory devices. The researchers have already created prototypes of the devices and are in the process of testing them. Multiferroic materials have both ferroelectric and ferromagnetic properties.
One challenge in improving the efficiency of solar cells is some of the absorbed light energy is lost as heat. So scientists have been looking to design materials that can convert more of that energy into useful electricity. Now a team from Brookhaven National Laboratory and Columbia Univ. has paired up polymers that recover some of that lost energy by producing two electrical charge carriers per unit of light instead of the usual one.
A team of chemistry and materials science experts from Univ. of California, Santa Barbara and The Dow Chemical Company has created a novel way to overcome one of the major hurdles preventing the widespread use of controlled radical polymerization.
Narrow strips of graphene called nanoribbons exhibit extraordinary properties that make them important candidates for future nanoelectronic technologies. A barrier to exploiting them, however, is the difficulty of controlling their shape at the atomic scale, a prerequisite for many possible applications.
A new type of nanowire crystals that fuses semiconducting and metallic materials on the atomic scale could lay the foundation for future semiconducting electronics. Researchers at the Univ. of Copenhagen are behind the breakthrough, which has great potential. The development and quality of extremely small electronic circuits are critical to how and how well future computers and other electronic devices will function.
Even when building big, every atom matters, according to new research on particle-based materials at Rice Univ. Rice researchers have published a study showing what happens at the nanoscale when “structurally complex” materials like concrete rub against each other. The scratches they leave behind can say a lot about their characteristics.
In a promising lithium-based battery, the formation of a highly conductive silver matrix transforms a material otherwise plagued by low conductivity. To optimize these multi-metallic batteries, scientists needed a way to see where, when and how these silver, nanoscale "bridges" emerge. Now, researchers have used x-rays to map this changing atomic architecture and revealed its link to the battery's rate of discharge.
Hair loss can be devastating for the millions of men and women who experience it. Now scientists are reporting that a substance from honeybee hives might contain clues for developing a potential new therapy. They found that the material, called propolis, encouraged hair growth in mice. The study appears in the Journal of Agricultural and Food Chemistry.
The best material to keep carbon dioxide from natural gas wells from fouling the atmosphere may be a derivative of asphalt, according to Rice Univ. scientists. The Rice laboratory of chemist James Tour followed up on last year’s discovery of a “green” carbon capture material for wellhead sequestration with the news that an even better compound could be made cheaply in a few steps from asphalt.
To stay warm when temperatures drop outside, we heat our indoor spaces—even when no one is in them. But scientists have now developed a novel nanowire coating for clothes that can both generate heat and trap the heat from our bodies better than regular clothes. They report on their technology, which could help us reduce our reliance on conventional energy sources, in Nano Letters.
Theorists and experimentalists working together at Cornell Univ. may have found the answer to a major challenge in condensed matter physics: identifying the smoking gun of why “unconventional” superconductivity occurs, they report in Nature Physics.
Researchers from the Univ. of Cambridge have developed a new self-assembled material, which, by changing its shape, can amplify small variations in temperature and concentration of biomolecules, making them easier to detect. The material, which consists of synthetic spheres “glued” together with short strands of DNA, could be used to underpin a new class of biosensors, or form the basis for new drug delivery systems.
A Northwestern Univ.-led team recently found the answer to a mysterious question that has puzzled the materials science community for years—and it came in the form of some surprisingly basic chemistry. Like many scientists, Jiaxing Huang didn't understand why graphene oxide films were highly stable in water.
Lead sulfide nanocrystals suitable for solar cells have a nearly one-to-one ratio of lead to sulfur atoms, but Massachusetts Institute of Technology (MIT) researchers discovered that to make uniformly sized quantum dots, a higher ratio of lead to sulfur precursors—24 to 1—is better.
At Penn State, a group led by Melik Demirel, professor of engineering science and mechanics, is designing a biodegradable plastic from structural proteins that could help clean up the world's oceans and solve an interesting set of other problems along the way.
Scientists have used advanced microscopy to carve out nanoscale designs on the surface of a new class of ionic polymer materials for the first time. The study provides new evidence that atomic force microscopy, or AFM, could be used to precisely fabricate materials needed for increasingly smaller devices.
New work from Carnegie Institute's Ivan Naumov and Russell Hemley delves into the chemistry underlying some surprising recent observations about hydrogen, and reveals remarkable parallels between hydrogen and graphene under extreme pressures.
In the fight against global warming, carbon capture is gaining momentum, but standard methods are plagued by toxicity, corrosiveness and inefficiency. Using a bag of chemistry tricks, Cornell Univ. materials scientists have invented low-toxicity, highly effective carbon-trapping “sponges” that could lead to increased use of the technology.
Just in time for Christmas, Simon Fraser Univ. computing science professor Richard Zhang reveals how to print a 3-D Christmas tree efficiently and with zero material waste, using the world’s first algorithm for automatically decomposing a 3-D object into what are called pyramidal parts. A pyramidal part has a flat base with the remainder of the shape forming upwards over the base with no overhangs, much like a pyramid.
New findings could provide a pathway toward a kind of 2-D microchip that would make use of a characteristic of electrons other than their electrical charge, as in conventional electronics. The new approach is dubbed “valleytronics,” because it makes use of properties of an electron that can be depicted as a pair of deep valleys on a graph of their traits.
One major challenge currently facing the graphene industry is difficulty in controlling the quality of graphene sheets when produced over large areas using industrial scale techniques. The key to solving this challenge lies in gaining a thorough understanding of the synthetic methods used to fabricate macro-sized single-layer graphene films.