Of all the standard units currently in use around the world, the kilogram is the only one that still relies on a physical object for its definition. But revising this outdated definition will require precise vacuum-based measurements that researchers are not yet able to make. A new system is in development that would allow a direct comparison of an object being weighed in a vacuum to one outside a vacuum.
Researchers at the Univ. of Colorado Boulder have successfully added a fourth dimension to their printing technology, opening up exciting possibilities for the creation and use of adaptive, composite materials in manufacturing, packaging and biomedical applications. The researchers incorporated “shape memory” polymer fibers into the composite materials used in traditional 3-D printing.
As microelectronics get smaller and smaller, one of the biggest challenges to packing a smartphone or tablet with maximum processing power and memory is the amount of heat generated by the tiny “switches” at the heart of the device. A complex metal-oxide film could help reduce the voltage required to switch electronic signals, and thus the excessive energy they require.
Scientists have used the powerful x-ray laser at the SLAC National Accelerator Laboratory to create movies detailing trillionths-of-a-second changes in the arrangement of copper atoms after an extreme shock. The study pinpointed the precise breaking point when the extreme pressures began to permanently deform the copper structure, or lattice, so it could no longer bounce back to its original shape.
A new study set out to use numerical simulations to validate previous theoretical predictions describing materials exhibiting so-called antiferromagneting characteristics. A recently discovered theory shows that the ordering temperature depends on two factors—namely the spin-wave velocity and the staggered magnetization. The simulations match these theoretical predictions.
Researchers have recently provided the first evidence ever that it is possible to generate a magnetic field by using heat instead of electricity. The phenomenon is referred to as the Magnetic Seebeck effect or “thermomagnetism”.
When it comes to designing extremely water-repellent surfaces, shape and size matter. That's the finding of a group of scientists at Brookhaven National Laboratory, who investigated the effects of differently shaped, nanoscale textures on a material's ability to force water droplets to roll off without wetting its surface.
Scientists at Brookhaven National Laboratory have developed a general approach for combining different types of nanoparticles to produce large-scale composite materials. The technique opens many opportunities for mixing and matching particles with different magnetic, optical or chemical properties to form new, multifunctional materials or materials with enhanced performance for a wide range of potential applications.
Materials in lithium ion battery electrodes expand and contract during charge and discharge. These volume changes drive particle fracture, which shortens battery lifetime. A group of scientists has quantified this effect for the first time using high-resolution 3D movies recorded using x-ray tomography at the Swiss Light Source.
Although the amount of data that can be stored has increased immensely during the past few decades, it is still difficult to actually store data for a long period of time. A researcher has recently demonstrated a way to store data for extremely long periods, even millions of years, using an etched wafer made of tungsten encapsulated by silicon nitride. The material is resistant to both time and elevated temperatures.
Vanadium dioxide is one of the few known materials that acts like an insulator at low temperatures but like a metal at warmer temperatures starting around 67 C. This temperature-driven metal-insulator transition, the origin of which is still intensely debated, could be induced by the application of an external electric field. Beamline studies at the Advanced Light Source has shed some light on this potential avenue for faster electronics.
Scientists have created a heat-resistant thermal emitter that could significantly improve the efficiency of solar cells. The novel component is designed to convert heat from the sun into infrared light, which can then be absorbed by solar cells to make electricity. Unlike earlier prototypes that fell apart at temperatures below 1,200 C, the new thermal emitter remains stable at temperatures as high as 1,400 C.
The silk of a spider feared for its venomous bite could be the key to creating new super-sticky films and wafer-thin electronics and sensors for medical implants that are highly compatible with the human body. A team of scientists studied the brown recluse spider (Loxosceles recluse), which produces super-thin ribbons of silk as opposed to the round fibers typically spun by spiders.
It was a result so unexpected that Massachusetts Institute of Technology researchers initially thought it must be a mistake: Under certain conditions, putting a cracked piece of metal under tension has the reverse effect, causing the crack to close and its edges to fuse together. The surprising finding could lead to self-healing materials that repair incipient damage before it has a chance to spread.
To gauge whether suspects involved in accidents or routine traffic stops have been driving drunk, police officers pair field sobriety tests with breathalyzers. Most breathalyzers are expensive and unable to test for precise concentrations of alcohol. Offering a better solution, Italian researchers have developed a novel idea for an inexpensive, portable breathalyzer.
Using ultra-fast laser pulses, a team of researchers led by the Univ. of Arizona has made the first detailed observation of how energy travels through diamonds containing nitrogen-vacancy centers—promising candidates for a variety of technological advances such as quantum computing.
Blowing bubbles in the backyard is one thing and quite another when searching for oil. That distinction is at the root of new research by Rice Univ. scientists who describe in greater detail than ever precisely how those bubbles form, evolve and act. The research describes two previously unknown ways that bubbles form in foam.
Univ. of Illinois researchers have developed a new approach with applications in materials development for energy capture and storage and for optoelectronic materials. According to Charles Schroeder, an asst. prof. in the Dept. of Chemical and Biomolecular Engineering, the results show that peptide precursor materials can be aligned and oriented during their assembly into polypeptides using tailored flows in microfluidic devices.
Atomically thin sheets of hexagonal boron nitride (h-BN) have the handy benefit of protecting what’s underneath from oxidizing even at very high temperatures, Rice Univ. researchers have discovered. One or several layers of the material sometimes called “white graphene” keep materials from oxidizing up to 1,100 C (2,012 F), and can be made large enough for industrial applications, they said.
Researchers in Japan have developed a new photodiode that can detect in just milliseconds a certain type of high-energy ultraviolet light, called UVC, which is powerful enough to break the bonds of DNA and harm living creatures. The new device shows promise for space-based communication and monitoring ozone depletion.
When a tiny droplet of liquid tin is heated with a laser, plasma forms on the surface of the droplet and produces extreme ultraviolet (EUV) light, which has a higher frequency and greater energy than normal ultraviolet. Now, for the first time, researchers have mapped this EUV emission and developed a theoretical model that explains how the emission depends on the 3-D shape of the plasma.
The Kavli Foundation has endowed a new institute at the Univ. of California, Berkeley, and the Lawrence Berkeley National Laboratory to explore the basic science of how to capture and channel energy on the molecular or nanoscale and use this information to discover new ways of generating energy for human use.
In a new white paper from Carl Zeiss Microscopy, scientists from DME Nanotechnologie GmbH and Zeiss demonstrate the power of the AFM/SEM combination found in the Zeiss Merlin series microscopes for the analysis of helium ion beam exposed nanostructures.
In a completely unexpected finding, Massachusetts Institute of Technology researchers have discovered that tiny water droplets that form on a superhydrophobic surface, and then “jump” away from that surface, carry an electric charge. The finding could lead to more efficient power plants and a new way of drawing power from the atmosphere, they say.
With a $855,000 grant from the U.S. Army Research Office, a trio of university researchers is proposing the development a new printing technology that adds a fourth dimension. By manipulating materials at the micro- and nanoscale dimensions, they hope to develop printable structures that can exhibit behavior that changes over time.