Stresses arise in thin films during the manufacture of read heads in hard drives, lasers, and computer chip transistors. This can cause crystal lattice defects and eventual component failure. Researchers have recently determined that enormous stresses, up to 1,000 times atmospheric pressure, can be created in thin films by a quantum-mechanical mechanism that has been unknown until now. It is based on an effect by the name of quantum confinement.
An invisible quick response (QR) code has been created by researchers in South Dakota in an attempt to increase security on printed documents and reduce the possibility of counterfeiting, a problem which costs governments and private industries billions of dollars each year. The QR code is made of tiny nanoparticles that have been combined with blue and green fluorescence ink, which is invisible until illuminated with laser light.
Scientists at the Norwegian University of Science and Technology report they have patented and are commercializing gallium arsenide (GaAs) nanowires grown on graphene. These semiconductors, which are being developed for market by the the company CrayoNano, are grown on atomically-thin graphene using molecular beam epitaxy.
Researchers have developed a new kind of anti-theft system, based on a woven fabric, that triggers an alarm when penetrated. Because of the fine lattice of conductive threads woven into the material, the fabric can notify the precise location of a failure, allowing the source of a break-in to be quickly identified. The invention could be significantly cheaper than other burglary detection systems.
For several years, experts in nanotechnology have suspected—but not proven—that quantum interference effects make the conductance of a circuit with two paths up to four times higher than the conductance of a circuit with a single path. By constructing their own controllable, molecular-scale circuits, scientists at Brookhaven National Laboratory have confirmed an increase in conductance. But not as large as was anticipated.
Engineers at Cornell University have invented a way to pattern single atom films of graphene and boron nitride, an insulator, without the use of a silicon substrate. The technique, called patterned regrowth, is reliant on conventional silicon photolithography technology and could lead to substrate-free circuits that would be atomically thin yet retain high tensile strength and superior electrical performance.
In attempt to achieve better control of heat flows in electronic devices, a researcher in Finland has invented two new mesoscopic devices based on the behavior of single electrons in a constructed system. The inventions, which include a diode, or rectifier, specifically address the heat carried by an electron and help produce a strongly asymmetric heat flow. The next step will be to manage larger currents.
Flat panel displays and mobile phones require thin, efficient, and low-cost light emitters, which are typically made from pixels wired to complex electronic circuits. Engineers in Singapore have now developed a display technology that requires a much simpler architecture: a thin perforated gold film with a liquid crystal layer.
A critical element in any microchip is an inverter—an electronic component that spits out zeros when it is given ones, and vice versa. Complementary metal-oxide-semiconductor, or CMOS, is the industry standard for this type of component, but still requires billions of dollars to achieve production scale. Researchers have recently pioneered a room-temperature additive process that creates a nanoscale inverter quickly and at low cost.
A team of organic chemists have discovered they can create very long crystals with desirable properties using just two small organic molecules that are extremely attracted to each other. The attraction between the two molecules causes them to self assemble into an ordered network, and, most importantly, they possess the ferroelectric properties that are useful in computing.
After making a sheet of “paper” from the world’s thinnest material, graphene, Rensselaer Polytechnic Institute scientists zapped it with a laser. The light blemished the ultrathin paper with countless cracks, pores, and other imperfections. The result is a graphene anode material that can be charged or discharged 10 times faster than conventional graphite anodes used in today’s lithium-ion batteries.
A team of researchers at in Japan has demonstrated a new material that promises to eliminate loss in electrical power transmission. Their methodology for solving this classic energy problem is based on a highly exotic type of magnetic semiconductor first theorized less than a decade ago—a magnetic topological insulator.
Scientists in Sweden report they have produced organic light-emitting electrochemical cells (LECs) using a roll-to-roll compatible process under ambient conditions. They say the innovation proves that LECs can be produced as inexpensive and thin, large-area light-emitting devices for informative displays and, at a later stage, lighting applications.
Researchers from two SLAC-Stanford University joint institutes recently joined forces to investigate a catalyst that promotes energy-releasing reactions in fuel cells. What they discovered, after using high-resolution X-ray spectrometry, is that two different platinum-rhodium nanostructures behaved in strikingly different ways. The finding indicated the importance of careful engineering in catalyst design.
Scientists at IBM Research and ETH Zurich in Switzerland report that they are the first to synchronize electron spins and image the formation of a persistent spin helix in a semiconductor. Until now, it was unclear whether electron spins could preserve encoded information long enough before rotating. This new work extends spin lifetime 30-fold, to 1.1 nanosec.
Multiferroics are expected to be applied to a new type of memory devices in which dielectric polarization is controlled by a magnetic field and magnetization is controlled by an electric field. However, multiferroic materials that function at room temperature are rare. In a breakthrough toward this goal, a team in Japan and the U.K. have achieved ferroelectric polarization without a magnetic field after discovering that they could swap out atoms and still maintain control of the multiferroic’s dielectric and magnetic properties.
Researchers at Argonne National Laboratory and in Switzerland have recently demonstrated the existence of long-lived charge-separated states in silver clusters. The stable charge-separated state, together with the fact that the clusters absorb light over a wide range of wavelengths, mean that the clusters represent a new and promising class of materials for solar energy applications.
Using a universal transfer approach, a team of engineers in Korea have built a flexible lithium-ion battery structured with high density inorganic thin films. The innovation has potential as an essential energy source for flexible displays.
In waveguides, such as those used in fiber optics, light has a tendency to reflect backwards, interfering with transmission of data. Today’s optical networks keep light from reflecting backward with devices called isolators. To help enable computer chips that operate with light, researchers at the Massachusetts Institute of Technology have invented a new metamaterial prevents electromagnetic waves from reflecting backward.
If recent research in Italy is an indication, the next generation of computing could be performed with silicene, an atomically thin form of silicon. The silicene structure consists of one atomic layer of silicon atoms and in this way it is analogous to graphene. With silicene, however, no modification is necessary to create a bandgap.
A recent study from Lawrence Berkeley National Laboratory offers the first direct observations and recordings of how electrons and holes respond to a charged impurity—a single Coulomb potential—placed on a gated graphene device. The results provide experimental support to the theory that interactions between electrons are critical to graphene’s extraordinary properties.
A research team has built an air-breathing battery that uses the chemical energy generated by the oxidation of iron plates that are exposed to the oxygen in the air—a process similar to rusting. The concept has been around for decades, but competing chemical reaction of hydrogen generation sucked away about 50% of the battery’s energy. Recent breakthroughs have lowered this loss to just 4%.
Computers often do not run as fast as they should because they are constantly transferring information between two kinds of memory: a fast, volatile memory connected to the CPU, and a slow, non-volatile memory that remembers data even when switched off. A special class of universal memory called spin-transfer torque magnetic random access memory (MRAM) being explored by researchers in Singapore could help avoid this bottleneck.
Plastic semiconductors have an important design flaw: The electronic current is influenced by poorly understood "charge traps" in the material. A new study by an international team of researchers reveals a common mechanism underlying these traps and provides a theoretical framework to design trap-free plastic electronics.
In a first for nanotechnology, a biophysicist in Switzerland has developed a method that measures not only the size of the particles but also their electrostatic charge. Up until the invention of this new approach, which relies on an “electrostatic trap”, it has not been possible to determine the charge of the particles directly.