You’ve probably seen it in your kitchen cookware, or inside old plumbing pipes: scaly deposits left over time by hard, mineral-laden water. It happens not only in pipes and cooking pots in the home, but also in pipelines and valves that deliver oil and gas, and pipes that carry cooling water inside power plants. Scale, as these deposits are known, causes inefficiencies, downtime and maintenance issues.
Sometimes solving a problem doesn’t require a high-tech solution. Sometimes, you have to look no farther than your desktop. Three students from Northwestern Univ.’s McCormick School of Engineering have proven that pencils and regular office paper can be used to create functional devices that can measure strain and detect hazardous chemical vapors.
Researchers in Ireland and Germany have discovered a novel solid state reaction which lets kesterite grains grow within a few seconds and at relatively low temperatures. The work points towards a new pathway for the fabrication of thin microcrystalline semiconductor films without the need of expensive vacuum technology.
In only a few years, the efficiency of perovskite-based solar cells has increased from 3% to more than 16%. However, a detailed explanation of the mechanisms of operation within this photovoltaic system is still lacking. in recent work, scientists have now uncovered the mechanism by which these novel light-absorbing semiconductors transfer electrons along their surface.
Researchers at North Carolina State Univ. have shown that a one-atom thick film of molybdenum sulfide (MoS2) may work as an effective catalyst for creating hydrogen. The work opens a new door for the production of cheap hydrogen. Hydrogen holds great promise as an energy source, but the production of hydrogen from water electrolysis currently relies in large part on the use of expensive platinum catalysts.
Researchers in California have created tactile sensors from composite films of carbon nanotubes and silver nanoparticles similar to the highly sensitive whiskers of cats and rats. These new e-whiskers respond to pressure as slight as a single Pascal, about the pressure exerted on a table surface by a dollar bill.
Physicists at the Univ. of Arkansas and their collaborators have engineered novel magnetic and electronic phases in the ultra-thin films of in a specific electronic magnetic material, opening the door for researchers to design new classes of material for the next generation of electronic and other devices.
Turbine manufacturers have employed special nickel-based high-performance “superalloys” for decades as a way to guarantee turbines maintain their chemical and mechanical properties almost to their melting point. New research shows in detail how new phases in a nickel-based alloy form and evolve during heat treatment, providing clues to how these high-performance alloys could be improved.
A new approach to harvesting solar energy, developed by Massachusetts Institute of Technology researchers, could improve efficiency by using sunlight to heat a high-temperature material whose infrared radiation would then be collected by a conventional photovoltaic cell. This technique could also make it easier to store the energy for later use, the researchers say.
Solid catalysts based on precious metals, such as palladium, are widely used in industry to promote a range of chemical reactions. Finding ways to minimize the consumption of expensive catalytic materials, however, remains a critical challenge. Researchers in Japan have now developed a nanostructured catalyst that makes extremely efficient use of trace amounts of catalytic palladium.
A carbon nanotube (CNT) sponge capable of soaking up water contaminants more than three times more efficiently than previous efforts has been presented in a new study. The CNT sponges, uniquely doped with sulfur, also demonstrated a high capacity to absorb oil, potentially opening up the possibility of using the material in industrial accidents and oil spill cleanups.
Using the interaction between light and charge fluctuations in metal nanostuctures called plasmons, a Univ. of Arkansas physicist and his collaborators have demonstrated the capability of measuring temperature changes in very small 3-D regions of space. In the experiments the team fabricated plasmonic nanostructures with electron beam lithography and precisely focused a laser on to a gold nanowire with a scanning optical setup.
A collaboration of researchers has discovered that sodium bismuthate can exist as a form of quantum matter called a 3-D topological Dirac semi-metal (3DTDS). This is the first experimental confirmation of 3-D Dirac fermions in the interior or bulk of a material, a novel state that was only recently proposed by theorists. It is a natural counterpart because of its magnetoresistive properties.
Rice Univ. scientists have found they can control the bonds between atoms in a molecule. The molecule in question is carbon-60, also known as the buckminsterfullerene and the buckyball, discovered at Rice in 1985. The scientists found that it’s possible to soften the bonds between atoms by applying a voltage and running an electric current through a single buckyball.
Researchers at the Univ. of Delaware have developed a “smart” hydrogel that can deliver medicine on demand, in response to mechanical force. Over the past few decades, smart hydrogels have been created that respond to pH, temperature, DNA, light and other stimuli.
Using an approach akin to assembling a club sandwich at the nanoscale, NIST researchers have succeeded in crafting a uniform, multi-walled carbon nanotube-based coating that greatly reduces the flammability of foam commonly used in upholstered furniture and other soft furnishings. The flammability of the nanotube-coated polyurethane foam was reduced 35% compared with untreated foam.
“The interface is the device,” Nobel laureate Herbert Kroemer famously observed, referring to the remarkable properties to be found at the junctures where layers of different materials meet. In today’s burgeoning world of nanotechnology, the interfaces between layers of metal oxides are becoming increasingly prominent. Realizing the vast potential of these metal oxide interfaces requires detailed knowledge of their electronic structure.
For decades, increasing amounts of data have been successfully stored on media with ever-higher densities. Now, an international team has discovered a physical phenomenon that could prove suitable for use in further data aggregation. Researchers found that domain walls, which separate areas in certain crystalline materials, display a polarization, potentially allowing information to be stored in the tiniest of spaces.
Researchers have shown how to increase the efficiency of thin-film solar cells, a technology that could bring low-cost solar energy. The approach uses 3-D photonic crystals to absorb more sunlight than conventional thin-film cells. The synthetic crystals possess a structure called an inverse opal to make use of and enhance properties found in the gemstones to reflect, diffract and bend incoming sunlight.
A new development by researchers at the Univ. of California, Berkeley, could lead to curtains and other materials that move in response to light, no batteries needed. Engineers have created a new light-reactive material made up of carbon nanotubes and plastic polycarbonate.
A new fabrication method inspired by blown sugar art has been used to make structure in which an ultrathin graphene layer, or layers, is glued to a 3-D strutted framework. The researchers in Japan, calling this the “chemical blowing method”, overcomes the weak intersheet connections that have made this type of structure so difficult to create in the past.
The field of metamaterials has produced structures with unprecedented abilities, including flat lenses, invisibility cloaks and even optical metatronic devices that can manipulate light in the way electronic circuitry manipulates the flow of electrons. Now, the birthplace of the digital computer, ENIAC, is using this technology in the rebirth of analog computing.
Scientists have grown sheets of an exotic material in a single atomic layer and measured its electronic structure for the first time. They discovered it’s a natural fit for making thin, flexible light-based electronics. In the study, the researchers give a recipe for making the thinnest possible sheets of the material, called molybdenum diselenide, in a precisely controlled way, using a technique that’s common in electronics manufacturing.
It's known that electric vehicles could travel longer distances before needing to charge and more renewable energy could be saved for a rainy day if lithium-sulfur batteries can just overcome a few technical hurdles. Now, a novel design for a critical part of the battery has been shown to significantly extend the technology's lifespan, bringing it closer to commercial use.
Researchers at Oak Ridge National Laboratory and the Univ. of Tennessee, Knoxville have pioneered a new technique for forming a 2-D, single-atom sheet of two different materials with a seamless boundary. The study could enable the use of new types of 2-D hybrid materials in technological applications and fundamental research.