Researchers in the U.K. have developed a method of controlling the composition of a range of polymers, the large molecules that are commonly used as plastics and fibers. They have demonstrated how the chemical reactions can be manipulated, especially in fixing the composition of a polymer using a mixture of up to three different monomers. The secret lies in understanding and switching “on” and “off” the catalyst used to make the polymers.
The scarcity of ultraviolet (UV) light in sunlight has held back the usefulness of titanium dioxide-based photocatalysts. Through the application of nanotechnology, researchers in Japan have recently succeeded in the development of better titanium dioxide-based material that can be activated by visible light. The solution lies in an array of nanoparticles that “simulate” the photoexcitation of UV light.
Univ. of Colorado Boulder scientists have found a creative way to radically improve thermoelectric materials, a finding that could one day lead to the development of improved solar panels and more energy-efficient cooling equipment. The technique, building an array of tiny pillars on top of a sheet of thermoelectric material, represents an entirely new way of attacking a century-old problem.
A multi-university team of engineers has developed what could be a promising solution for charging smartphone batteries on the go, without the need for an electrical cord. Incorporated directly into a cell phone housing, the team's nanogenerator could harvest and convert vibration energy from a surface, such as the passenger seat of a moving vehicle, into power for the phone.
Computers don’t need to be error-free. They just need to correct their errors reliably, which means that controlling a quantum system is crucial to the function of a quantum computer. A research team has now found a way to control the quantum system of a diamond which has a few nitrogen impurities. They have used the system to perform a logic operation and error correction in a quantum register made from nuclear spins of the gemstone.
The 2014 Sochi Olympics were expected to be a triumphant moment for the U.S. speedskating team—and the squad's sponsor, Under Armour. It's been anything but that. After a strong showing on the World Cup circuit, the team headed to the Games in skinsuits that Under Armour developed and called the fastest speedskating suits in the world.
Clemson Univ. researchers have developed nanoparticles that can deliver drugs targeting damaged arteries, a non-invasive method to fight heart disease. Heart disease is the leading cause of death in the U.S., according to the Centers for Disease Control and Prevention. One of the standard ways to treat clogged and damaged arteries currently is to implant vascular stents, which hold the vessels open and release such drugs as paclitaxel.
An electrode designed like a pomegranate—with silicon nanoparticles clustered like seeds in a tough carbon rind—overcomes several remaining obstacles to using silicon for a new generation of lithium-ion batteries, say its inventors at Stanford Univ. and the SLAC National Accelerator Laboratory.
Scientists have created a microbattery that packs twice the energy compared to current microbatteries used to monitor the movements of salmon through rivers in the Pacific Northwest and around the world. The battery, a cylinder just slightly larger than a long grain of rice, is certainly not the world's smallest battery, as engineers have created batteries far tinier than the width of a human hair.
On a pound-per-pound basis, carbon nanotube-based fibers invented at Rice Univ. have greater capacity to carry electrical current than copper cables of the same mass, according to new research. While individual nanotubes are capable of transmitting nearly 1,000 times more current than copper, the same tubes coalesced into a fiber using other technologies fail long before reaching that capacity.
Superconductor “recipes” are frequently tweaked by swapping out elements or manipulating the valence electrons to strike the perfect conductive balance. Most high-temperature superconductors feature only one orbital impacting performance. But what about introducing more complex configurations? Now, Brookhaven National Laboratory’s physicists have combined atoms with multiple orbitals and precisely pinned down their electron distributions.
An undesired effect in thin film amorphous silicon solar cells has puzzled the scientific community for the last 40 years. This effect, known as light-induced degradation, is responsible for reducing solar cell efficiency over time. Researchers in Germany have recently demonstrated that tiny voids within the silicon network are partly responsible for 10 to 15% efficiency loss as soon as they are used.
A team in France has greatly miniaturized the light-emitting diode (LED) by creating one from a single polythiophene wire placed between the tip of a scanning tunneling microscope and a gold surface. This nanowire, which is made of the same hydrogen, carbon and sulfur components found in much larger LEDs, emits light only when the current passes in a certain direction.
Once the snow melts, the bee population will be back in business pollinating and making honey. A new study by scientists in Canada reveals that some these bees use bits of plastic bags and plastic building materials to construct their nests. The discovery reveals how urban bee populations have adapted to a human-dominated world.
An international team has recently unveiled a superconducting pairing mechanism in calcium-doped graphene. The pairing, which was using a angle-resolved photoemission spectroscopy method, is important because graphene is easily doped or functionalized with chemicals, allowing scientists to more fully explore the nature of superconductivity.
Engineers are increasingly turning to plasmonic color filters (PCFs) to create and control a broad spectrum of colors for imaging applications. However, PCF light transmission efficiency has been limited to only about 30%, less than half the rate of conventional filters. Researchers have now developed a new PCF scheme that achieves a transmission efficiency of 60 to 70%.
NIST and American Univ. researchers report in a new study that the bench-scale test widely used to evaluate whether a burning cigarette will ignite upholstered furniture may underestimate the tendency of component materials to smolder when these materials are used in sofas and chairs supported by springs or cloth. The study comes as regulations and methods for evaluating ignition in furniture are undergoing scrutiny.
Inspired by tiny particles that carry cholesterol through the body, Massachusetts Institute of Technology chemical engineers have designed nanoparticles that can deliver snippets of genetic material that turn off disease-causing genes. This approach, known as RNA interference, holds great promise for treating cancer and other diseases. However, delivering enough RNA to treat the diseased tissue has proven difficult.
Materials experts in Ireland have developed a new germanium nanowire-based anode that has the ability to greatly increase the capacity and lifetimes of lithium-ion batteries. The typical lithium-ion battery on the market today is based on graphite, which has a relatively low capacity for energy storage. Restructuring the germanium replacement material into nanowires produces a stable, porous battery material.
A team of physicists have used statistical mechanics and mathematical modeling to shed light on something known as epigenetic memory, which allows an organism to create a biological memory of some variable condition, such as quality of nutrition or temperature. The model highlights the "engineering" challenge a cell must constantly face during molecular recognition.
U.S. Army-sponsored researchers have discovered a process for simultaneously storing and dissipating energy within structures that could lead to design rules for new types of active, reconfigurable materials. The study method was derived from an examination of how a species of South American fire ant collectively entangle themselves to form an active structure capable of changing state from a liquid to a solid when subject to applied loads.
Topological insulators have been of great interest to physicists in recent years because of unusual properties that may provide insights into quantum physics. But most analysis of such materials has had to rely on highly simplified models. Now, a team of researchers at Massachusetts Institute of Technology has performed a more detailed analysis that hints at the existence of six new kinds of topological insulators.
Lead-free BaTiO3 and KNbO3 ferroelectrics have been known and studied for more than 60 years. However, recent scanning x-ray diffraction studies at Argonne National Laboratory have shown new low-symmetry intermediate phases in these materials that lend a thermotropic character to otherwise well-known phase transitions. The findings show that these transitions in ferroelectrics are closely coupled to the underlying domain microstructure.
An international team of researchers from France and the United States have devised an entirely new way to synthesize graphene ribbons with defined, regular edges, allowing electrons to flow freely through the material. Demonstrating this phenomenon at room temperature, the material was shown to permit electron flow up to 200 times faster than through silicon.
Texas Advanced Computing Center recently reported the results of several massive numerical simulations charting the forces of the universe in its first hundreds of millions of years. The study, which used some of the world's most powerful supercomputers, has refined our understanding of how the first galaxies formed, and, in particular, how metals in the stellar nurseries influenced the characteristics of the stars in the first galaxies.