Batteries don’t age gracefully. The lithium ions that power portable electronics cause lingering structural damage with each cycle of charge and discharge, making devices from smartphones to tablets tick toward zero faster and faster over time. To stop or slow this steady degradation, scientists must track and tweak the imperfect chemistry of lithium-ion batteries with nanoscale precision.
Although the potential uses for graphene seem limitless, there has been no easy way to scale up from microscopic to large-scale applications without introducing defects. Researchers in Chicago and Korea have recently developed a supersonic spray system that produces very small droplets of graphene which disperse evenly, evaporate rapidly, and reduce aggregation tendencies. And, to the researchers’ surprise, it also eliminates defects.
Using a doped-graphene matrix to slow down and then trap atoms of the precious metal osmium, researchers in the U.K. have shown the ability to control and quantify the growth of metal-crystals. When the trapped atoms come into contact with further osmium atoms they bind together, eventually growing into 3-D metal-crystals. They have called this new technique nanocrystallometry.
Solar cell technology has advanced rapidly, as hundreds of groups around the world pursue more than two dozen approaches using different materials, technologies and approaches to improve efficiency and reduce costs. Now a team at Massachusetts Institute of Technology has set a new record for the most efficient quantum-dot cells.
Using molecules of DNA like an architectural scaffold, Arizona State Univ. scientists, in collaboration with colleagues at the Univ. of Michigan, have developed a 3-D artificial enzyme cascade that mimics an important biochemical pathway that could prove important for future biomedical and energy applications.
Fancy Erector Set? Nope. The elaborate fractal structure shown at left is many, many times smaller than that and is certainly not child's play. It’s the latest example of a fractal nanotruss—nano because the structures are made up of members that are as thin as 5 nm; truss because they are carefully architected structures that might one day be used in structural engineering materials.
In response to requests from the semiconductor industry, a team of researchers at the Physical Measurement Laboratory has demonstrated that atomic force microscope probe tips made from its near-perfect gallium nitride nanowires are superior in many respects to standard silicon or platinum tips. They also found a way to use the tips as LEDs to illuminate sample regions while scanning.
Images taken by Rice Univ. scientists show that some diamonds are not forever. The Rice researchers behind a new study that explains the creation of nanodiamonds in treated coal also show that some microscopic diamonds only last seconds before fading back into less-structured forms of carbon under the impact of an electron beam.
Researchers have found that a particular species of quantum dots that weren't commonly thought to blink, do. So what? Well, although the blinks are short, even brief fluctuations can result in efficiency losses that could cause trouble for using quantum dots to generate photons that move information around inside a quantum computer or between nodes of a future high-security internet based on quantum telecommunications.
Melanin—and specifically, the form called eumelanin—is the primary pigment that gives humans the coloring of their skin, hair and eyes. It protects the body from the hazards of ultraviolet and other radiation that can damage cells and lead to skin cancer, but the exact reason why the compound is so effective at blocking such a broad spectrum of sunlight has remained something of a mystery.
A team in Texas has built the smallest, fastest and longest-running tiny synthetic motor to date. The reliable, 18,000-rpm device can convert electrical energy into mechanical motion on a scale 500 times smaller than a grain of salt. Made from three parts, the nanomotor can rapidly mix and pump biochemicals and move through liquids.
Brigham Young Univ. engineering professors Julie Crockett and Dan Maynes have created a sloped channel that is super-hydrophobic, and causes water to bounce like a ball as it rolls down the ramp. Their recent study finds surfaces with a pattern of microscopic ridges or posts, combined with a hydrophobic coating, produces an even higher level of water resistance, depending on how the water hits the surface.
A team led by researchers from the Univ. of California, Los Angeles has developed a new process to control molecular growth within the "building block" components of inorganic materials. The method, which uses nanoparticles to organize the components during a critical phase of the manufacturing process, could lead to innovative new materials, such as self-lubricating bearings for engines.
Modern supercapacitors store ten times less energy than a lithium-ion battery but can last a thousand times longer. The main drawback of supercapacitors, however, is the inability to cope with stresses such as pressure and vibration. Researchers have developed a new supercapacitor that operates flawlessly in storing and releasing electrical charge while subject to stresses or pressures up to 44 psi and vibrational accelerations over 80 g.
Researchers at the Univ. of California, Riverside have developed a new nanometer scale ruthenium oxide anchored nanocarbon graphene foam architecture that improves the performance of supercapacitors. They found that the new structure could operate safely in aqueous electrolyte and deliver two times more energy and power compared to supercapacitors commercially available today.
Graphene continues to reign as the next potential superstar material for the electronics industry, a slimmer, stronger and much faster electron conductor than silicon. With no natural energy bandgap, however, graphene’s superfast conductance can’t be switched off, a serious drawback for transistors and other electronic devices.
Using a material found in Silly Putty and surgical tubing, a group of researchers at the Univ. of California, Riverside Bourns College of Engineering have developed a new way to make lithium-ion batteries that will last three times longer between charges compared to the current industry standard. The innovation involves the development of silicon dioxide nanotube anodes.
A new approach to integrated circuits, combining atoms of semiconductor materials into nanowires and structures on top of silicon surfaces, shows promise for a new generation of fast, robust electronic and photonic devices. Engineers in California have recently demonstrated 3-D nanowire transistors using this approach that open exciting opportunities for integrating other semiconductors, such as gallium nitride, on silicon substrates.
A research team that figured out how to coat an organic material as a thin film wanted a closer look at why their spreadable organic semiconductor grew like it did. So Cornell Univ. scientists used their high-energy synchrotron x-ray source to show how these organic molecules formed crystal lattices at the nanoscale. These high-speed movies could help advance the technology move from the laboratory to mass production.
A simple new technique to form interlocking beads of water in ambient conditions could prove valuable for applications in biological sensing, membrane research and harvesting water from fog. Researchers have developed a method to create air-stable water droplet networks known as droplet interface bilayers. These interconnected water droplets have many roles in biological research because their interfaces simulate cell membranes.
Optical metamaterials harness clouds of electrons called surface plasmons to manipulate and control light. However, plasmonic devices often use gold or silver, which is incompatible with CMOS manufacturing processes. Purdue Univ. scientists have now developed an ultra-thin crystalline superlattice that instead uses metal-dielectrics. Applied using epitaxy, this “hyperbolic” film could greatly expand applications for metamaterials.
Researchers in Australia have created a micrometer thin film with record-breaking optical nonlinearity suitable for high-performance integrated photonic devices. To create the thin film the researchers spin coated graphene oxide solution to a glass surface. Using a laser as a pen they created microstructures on the graphene oxide film to tune the nonlinearity of the material.
Massachusetts Institute of Technology researchers have devised a novel cancer treatment that destroys tumor cells by first disarming their defenses, then hitting them with a lethal dose of DNA damage. In studies with mice, the research team showed that this one-two punch, which relies on a nanoparticle that carries two drugs and releases them at different times, dramatically shrinks lung and breast tumors.
Based on recent experiments and computer simulations, scientists at the Max Planck Institute for Polymer Research and the National Univ. of Singapore have attested that the thermal conductivity of graphene diverges with the size of the samples. This discovery challenges the fundamental laws of heat conduction for extended materials.
For years, scientists have had an itch they couldn’t scratch. Even with the best microscopes and spectrometers, it’s been difficult to study molecules at the mesoscale, a region of matter that ranges from 10 to 1,000 nm. Now, with the help of broadband infrared light from the Advanced Light Source synchrotron, researchers have developed a broadband imaging technique that looks inside this realm with unprecedented sensitivity and range.