A new analytical theory has been developed at Purdue University that shows how to design experiments to study ways of controlling dendrite growth on electrodes in lithium-ion batteries. Using this approach, the researchers have shown theoretically how to control or eliminate the formation of these dendrites, which cause lithium-ion batteries to fail. The advance could help improve safety and might enable the batteries to be charged within a matter of minutes instead of hours.
As one crucial step of achieving controllable quantum devices, physicists at the University of California Santa Barbara have developed an unprecedented level of manipulating light on a superconducting chip. In their experiment, they caught and released photons in and from a superconducting cavity by incorporating a superconducting switch.
A multi-university team of researchers has artificially engineered a unique multilayer material with tailorable properties. It seamlessly alternates between metal and oxide layers, achieving extraordinary superconducting properties such as the ability to transport much more electrical current than non-engineered materials. A superlattice, it is composed of 24 layers that alternate between pnictide superconductor and the oxide strontium titanate.
Just like electronics, living cells use electrons for energy and information transfer. But cell membranes have thus far prevented us from “plugging” in cells to our computers. To get around this barrier that tightly controls charge balance, a research group at Lawrence Berkeley National Laboratory’s Molecular Foundry has engineered <em>E. coli</em> as a testbed for cellular-electrode communication. They have now demonstrated that these bacterial strains can generate measurable current at an anode.
Northwestern University’s Yonggang Huang and the University of Illinois’ John A. Rogers are the first to demonstrate a stretchable lithium-ion battery—a flexible device capable of powering their innovative stretchable electronics. Their battery continues to work—powering a commercial light-emitting diode (LED)—even when stretched, folded, twisted and mounted on a human elbow. The battery can work for eight to nine hours before it needs recharging, which can be done wirelessly.
Electromagnetic devices, from power drills to smart-phones, require an electric current to create the magnetic fields that allow them to function. But researchers at the University of California, Los Angeles have developed a method for switching tiny magnetic fields on and off with an electric field—a sharp departure from the traditional approach of running a current through a wire. The new composite can control magneto-electric activity at a scale of just 10 nm.
To make fuel cells more economical, engineers want a fast and efficient iron-based molecule that splits hydrogen gas to make electricity. Researchers at Pacific Northwest National Laboratory have recently reported the development of such a catalyst. Made from a synthetic molecule, it is the first iron-based catalyst that converts hydrogen directly to electricity, and it might help make those fuel cells less expensive.
A recurring problem in organic electronics technology has been the difficulty in establishing good electrical contact between the active organic layer and metal electrodes. Organic molecules are frequently used for this purpose, but, until recent research at the Helmholtz Center in Germany unraveled this mystery, it was practically impossible to accurately predict which molecules performed well on the job.
The size of electronic components is reaching a physical limit. While 3D assembly can reduce bulk, the challenge is in manufacturing these complex electrical connections. Biologists and physicists in France have recently developed a system of self-assembled connections using actin filaments for 3D microelectronic structures. Once the actin filaments become conductors, they join the various components of a system together.
Recent research shows that a newly discovered class of materials, called layered oxide heterostructures, could have optimal electrical characteristics. A research team at the Vienna University of Technology, together with colleagues from the United States and Germany, has now shown that these heterostructures can be used to create a new kind of extremely efficient ultra-thin solar cells.
Like turning coal to diamond, adding pressure to an electrical material enhances its properties. Now, University of Illinois at Urbana-Champaign researchers have devised a method of making ferroelectric thin films with twice the strain, resulting in exceptional performance.
Scientists from the U.S. Department of Energy’s National Renewable Energy Laboratory and other labs have demonstrated a process whereby quantum dots can self-assemble at the apex of a gallium arsenide-aluminum gallium arsenide core-shell nanowire interface. This activity at optimal locations in nanowires could improve solar cells, quantum computing, and lighting devices.
Researchers have tried for decades to replicate the effects of transistors in transition metal oxides by using a voltage to convert the material from an insulator to a metal, but the induced change only occurs within a few atomic layers of the surface. Recently, however, scientists in Japan have discovered that applying a voltage to a vanadium dioxide film several tens of nanometers thick converts the entire film from an insulator to a metal.
Research by an international team of physicists has produced new methods for controlling magnetic order in a particular class of materials known as "magnetoelectrics", which have their magnetic and electric properties couple to each other. This link offers the possibility of controlling electric behavior with a magnetic signal, or vice versa. Scientists recently demonstrated this ability in europium-titanium oxide.
Thermoelectric efficiency has improved enough to enable limited commercial use, but lack of better materials has prevented widespread adoption. New development work at Massachusetts Institute of Technology could help reduce thermal conductivity while keeping electrical conductivity high. In addition to computer modeling, the researchers draw upon methods developed by optics researchers who have been attempting to create invisibility cloaks—ways of making objects invisible to certain radio waves or light waves using nanostructured materials that bend light.
Iridescence, or sheen that shifts color depending on your viewing angle, is pretty in peacock feathers. But it's been a nuisance for engineers trying to mimic the birds' unique color mechanism to make high-resolution, reflective, color display screens. Researchers at the University of Michigan have found a way to lock in so-called structural color, which is made with texture rather than chemicals. The finding could lead to advanced color e-books, electronic paper, and screens that don't need their own light to be readable.
For years, scientists have studied the potential benefits of a new branch of solar energy technology that relies on incredibly small nanosized antenna arrays that are theoretically capable of harvesting more than 70% of the sun’s electromagnetic radiation and simultaneously converting it into usable electric power. A new fabrication technique developed by University of Connecticut engineering professor Brian Willis could provide the breakthrough for this technology.
Organic semiconductors hold promise for making low-cost flexible electronics—if they can perform in spite of frequent flexing and sharp bending. Scientists have recently demonstrated extremely flexible organic semiconductors that withstood multiple bending cycles in which the devices were rolled to a radius as small as 200 μm. The scientists worked with numerous crystalline devices they made and found no degradation in their performance.
An international team of researchers affiliated with Göttingen University in Germany has found a way to store vast amounts of data—up to one petabyte—per square inch. The scientists developed a unique molecule with an exploitable electron that carries a spin. This serves as the memory for their electronic device, which can be read out by a magnetic reference electrode at room temperature.
Scientists from the University of Cambridge, U.K., have created, for the first time, a new type of microchip which allows information to travel in three dimensions. The chip’s design relies on spintronics, a technology that makes use of an electron's tiny magnetic moment, or “spin”, to store information. Currently, microchips can only pass digital information in a very limited way—from either left to right or front to back.
Two Rutgers University physics professors have proposed an explanation for a new type of order, or symmetry, in an exotic material made with uranium—a theory that may one day lead to enhanced computer displays and data storage systems and more powerful superconducting magnets for medical imaging and levitating high-speed trains.
Found in flat screens, solar modules, or in new organic light-emitting diode (LED) displays, transparent electrodes have become ubiquitous. But since raw materials like indium are becoming more and more costly, researchers have begun to look elsewhere for alternatives. A new review article sheds some light on the different advantages and disadvantages of established and new materials for use in these kinds of contact electrodes.
Physicists have recently demonstrated that the application of a very strong alternating electric field to thin liquid crystal cells leads to a new distinct nonlinear dynamic effect in the response of the cells. Researchers were able to explain this result through spatio-temporal chaos theory. The finding has implications for the operation of liquid crystal devices because their operation depends on electro-optic switch phenomena.
At the heart of computing are tiny crystals that transmit and store digital information's ones and zeroes. Today these are hard and brittle materials. But cheap, flexible, nontoxic organic molecules may play a role in the future of hardware. A team led by the University of Washington and the Southeast University discovered a molecule that shows promise as an organic alternative to today's silicon-based semiconductors.
Researchers in Germany have developed a new generation of image sensors that are more sensitive to light than the conventional silicon versions. Simple and cheap to produce, they consist of electrically conductive plastics which are sprayed onto the sensor surface in an ultra-thin layer. The chemical composition of the polymer spray coating can be altered so that even the invisible range of the light spectrum can be captured.