Engineers in Israel have created a radically new design for a concentrator solar cell that, when irradiated from the side, generates solar conversion efficiencies which rival, and may eventually surpass, the most efficient photovoltaics. The design, the developers say, can exceed 40% conversion efficiency at intensities of 10,000 suns.
Conventional giant magnetoresistive devices or ferromagnetic tunnel junction devices provide only low frequency oscillation and have been deemed unsuitable for applications requiring millimeter-wave (30-300 GHz) oscillation, including radar. Researchers in Japan have recently demonstrated, however, that oscillations of 5 to 140 GHz is theoretically possible in these devices by supplying direct current.
Scientists at NIST have created the first controllable atomic circuit that functions analogously to a superconducting quantum interference device (SQUID) and allows operators to select a particular quantum state of the system at will. By manipulating atoms in a superfluid ring thinner than a human hair the investigators were able for the first time to measure rotation-induced discrete quantized changes in the atoms’ state, thereby providing a proof-of-principle design for an “atomtronic” inertial sensor.
Wireless sensor networks monitor machinery and equipment in factories, cars and power stations. They increasingly “harvest” the energy they need to transmit measurement data from the environment, thus making them self-sufficient. At the Electronica 2012 trade fair, researchers will present a printed thermogenerator, which they say will be able to generate energy supply for sensors through temperature differences.
An experimental device invented at the University of Michigan is able to convert energy from a beating heart, enough to provide electricity to power a pacemaker. The innovation, which relies on piezoelectricity, could eliminate the need for surgeries to replace pacemakers with depleted batteries.
Scientists have recently developed a high-performance superconducting material by mixing iron and selenium in a new chemistry. Although this class of superconductors has already existed, the new material is the first to break the 44 Kelvin barrier. It also shows that iron-selenium superconductors can be successfully synthesized to a high degree of purity.
Solar, wind and other renewable energy sources reduce consumption of fossil fuels but also pose challenges to the electrical grid because their power generation fluctuates. A team of researchers at Stanford and SLAC National Accelerator Laboratory has developed a mix of materials that shows promise as a cost-effective alternative to standard batteries—able to quickly and efficiently charge and discharge their energy over thousands of charges, with no energy loss after 1,000 charges.
A Rice University team has hit upon a method to produce nearly transparent films of electrically conductive carbon nanotubes. Slides dipped into a solution of pure nanotubes in chlorosulfonic acid, the researchers found, left them with an even coat of nanotubes that, after further processing, had none of the disadvantages seen with other methods. The films may be suitable for flexible electronic displays and touchscreens.
Synchrotron-based imaging has helped develop enhanced light-emitting diode (LED) displays using bottom-up engineering methods. Collaborative work between researchers from the University of Florida and Cornell University has produced a new way to make colloidal "superparticles" from oriented nanorods of semiconducting materials.
A multinational research team has discovered filamentous bacteria that function as living power cables in order to transmit electrons thousands of cell lengths away. These cells are so tiny that they are invisible to the naked eye. And yet, under the right circumstances, they form a multicellular filament that can transmit electrons across a distance as large as 1 cm as part of the filament’s respiration and ingestion processes.
One of the keys to exploiting graphene's potential is being able to create atomic-scale defects as these influence its electrical, chemical, magnetic, and mechanical properties. A team of materials experts have recently report a new approach to engineering graphene's atomic structure with unprecedented spatial precision.
Thanks to an ultrasensitive accelerometer—a type of motion detector—developed by researchers at the California Institute of Technology and the University of Rochester, a new class of microsensors is a step closer to reality. Instead of using an electrical circuit to gauge movements, this accelerometer uses laser light and is so sensitive it could be used to navigate shoppers through a grocery aisle or even stabilize fighter jets.
A research team in Japan has succeeded in developing equipment that enables simple, high speed measurement of the band diagrams of organic semiconductor materials in atmospheric conditions. The device essentially combines a spectrophotometer system for studying band gaps with a photoemission yield system to examine ionized potential.
People can let their fingers—and hands—do the talking with a new touch-activated system that projects onto walls and other surfaces and allows users to interact with their environment and each other. Developed at Purdue University, the "extended multitouch" system allows more than one person to use a surface at the same time and also enables people to use both hands, distinguishing between the right and left hand.
In 1937, Italian physicist Ettore Majorana predicted the existence of a class of particle that would serve as its own antiparticle. Such a particle might exist as a quasiparticle, or collection of excitons. Some scientists believe that qubits made from these Majorana “pulses”, when excited in topological materials, would be much more immune from decoherence than other qubits based on conventional particles.
Because conventional solar cells lose all of the energy available from the infrared portion of the solar spectrum, researchers have been investigating photovoltaics that can convert this lost energy. Black silicon is one material which can do this, researchers in Germany have recently managed to double the efficiency of black silicon solar cells by modifying the shape of the laser pulse used to irradiate the silicon.
When stretched, a layer of silicon can build up internal mechanical strain which can considerably improve its electronic properties. Using this principle, engineers have developed a method which allows them to produce 30-nm-thick highly strained wires in a silicon layer. This strain is the highest that has ever been observed in a material which can serve as the basis for electronic components.
The ability to determine the composition and physics of nanoscale materials and devices at NIST is about to improve dramatically with the arrival of a new near-field scanning microwave microscope (NSMM) design. Researchers there, using existing commercial and homemade NSMMs, have pioneered many applications, notably including determination of semiconductor dopant distribution in 2D and 3D. Now they hope to look at mechanical and magnetic resonance on the nanoscale.
Optical force refers to the way beams of light can be made to attract or repel each other, as magnets do. Researchers at Missouri University of Science and Technology, in a study that gauged this type of force at the nanoscale, report that a new class of nanoscale slot waveguides pack 100 to 1,000 times more transverse optical force than conventional silicon slot waveguides.
Within optical microchips, light finds its way through waveguides made of silicon, and is amplified with the help of other semiconductors, such as gallium arsenide and erbium. But until recent work in The Netherlands, no chip existed on which both silicon and erbium-doped material had been successfully integrated. The new chip now amplifies light up to 170 Gbit/sec.
Belgium-based semiconductor manufacturing firm imec announced Tuesday that it has integrated an ultra-thin, flexible chip with bendable and stretchable interconnects into a package that adapts dynamically to curving and bending surfaces. The resulting circuitry can be embedded in medical and lifestyle applications where user comfort and unobtrusiveness is key, such as wearable health monitors or smart clothing.
As part of their investigation of the effects ionizing radiation has on crystalline structures found in single-walled carbon nanotube transistors, U.S. Naval Research Laboratory engineers have recently shown these devices can stand up harsh space environments. This durability has been achieved through a combination of a hardened dielectric material and the natural isolation of the transistor.
An international team of scientists has discovered a new class of materials that could prove to be useful in developing new methods of creating computer memory. The research team explored layered heterostructures at the atomic scale, in which different materials were deposited in layers a few atoms thick. They discovered that the new class of materials boasts an attractive property—ferroelectricity.
Probe storage devices read and write data by making nanoscale marks on a surface through physical contact, but they currently have limited lifespans due to mechanical wear. A research team, led by Intel Corp., has now developed a long-lasting ultrahigh-density probe storage device by coating the tips of the probes with a thin metal film. The technology may one day extend the data density limits of conventional magnetic and optical storage.
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.