In Harvard University's Pierce Hall, the surface of a small germanium-coated gold sheet shines vividly in crimson. A centimeter to the right, where the same metallic coating is literally only about 20 atoms thicker, the surface is a dark blue, almost black. The colors from the logo of the Harvard School of Engineering and Applied Sciences, where researchers have demonstrated a new way to customize the color of metal surfaces by exploiting an overlooked optical phenomenon.
Making uniform coatings is a common engineering challenge, and, when working at the nanoscale, even the tiniest cracks or defects can be a big problem. New research from University of Pennsylvania engineers has shown a new way of avoiding such cracks when depositing thin films of nanoparticles based on spin-coating.
The theoretical and experimental framework of a new coherent diffraction strain imaging approach was recently developed by scientists at IBM and Argonne National Laboratory. The new technique is capable of imaging lattice distortions in thin films nondestructively at spatial resolutions of less than 20 nm using coherent nanofocused hard X-rays.
New technologies in microelectronics and lithography typically require the presence of nanoscale polymer films in contact with a substrate. Successful engineering of these structures requires an understanding of the interplay between the dynamics of the thin film and the underlying substrate, and recent experiments at the Argonne National Laboratory’s Advanced Photon Source have produced new insights into these compositions.
Researchers from North Carolina State University and the Georgia Institute of Technology have demonstrated a less-expensive way to create textured nickel ferrite (NFO) ceramic thin films, which can easily be scaled up to address manufacturing needs. NFO is a magnetic material that holds promise for microwave technologies and next-generation memory devices.
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.
A team led by Oak Ridge National Laboratory has discovered a strain relaxation phenomenon in cobaltites that has eluded researchers for decades and may lead to advances in fuel cells, magnetic sensors, and a host of energy-related materials. The finding could change the conventional wisdom that accommodating the strain inherent during the formation of epitaxial thin films involves structural defects.
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.
If recent research in Norway is successful, a coating filled with tiny lubricant capsules could come to the rescue when metal surfaces dry out and friction builds up. As part of a project at the Gemini Tribology Centre researchers are now testing whether it is possible—where two metal surfaces are in contact with each other—to apply a coating to surfaces formed of hard particles and capsules filled with liquid lubricant.
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.
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.
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.
Vivek Dwivedi, a technologist at NASA's Goddard Space Flight Center is experimenting with an emerging technology that might provide an effective technique for defending sensitive spacecraft components from the high-velocity bombardments. Using atomic layer deposition, he is applying a new super-strong, ultra-thin coating made of tiny tubes of boron nitride, similar in appearance to the bristles on a toothbrush.
Films made of semiconductor nanocrystals are seen as a promising new material for a wide range of applications. The size of a semiconductor nanocrystal determines its electrical and optical properties. But it's hard to control the placement of nanocrystals on a surface in order to make structurally uniform films. Now, researchers at Massachusetts Institute of Technology say they have found ways of making defect-free patterns of nanocrystal films where the shape and position of the films are controlled with nanoscale resolution.
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.
Thin, conductive films are useful in displays and solar cells. A new solution-based chemistry developed at Brown University for making indium tin oxide films could allow engineers to employ a much simpler and cheaper manufacturing process.
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 group of Massachusetts Institute of Technology engineers has discovered a way of making perfectly ordered and repeatable surfaces with patterns of microscale wrinkles. The method involves chemical vapor deposition of a layer onto a stretched silicon-polymer substrate. When tension is released first one way, then the other, a perfectly ordered wrinkled pattern emerges.
Biofilms stick to just about everything, from copper pipes to steel ship hulls to glass catheters, and can be both a nuisance and a health threat. A team of Harvard University scientists has developed a slick 99%-effective way to prevent the troublesome bacterial communities from ever forming on a surface.
Superhydrophobic surfaces, such as the lotus leaf, are excellent at repelling water and also boast other "smart" self-cleaning, anti-glare, anti-icing, and anti-corrosion properties. By using hollow silica nanoparticles that resemble raspberries, scientists in China have applied a clear, slick, water-repellent surface to glass.
Using a new side-view imaging technique, scientists in the U.K. have shown that their method for sandwiching individual graphene sheets between insulating layers in order to produce electrical devices works almost perfectly, even when more than 10 different layers are used to build the stack.
Researchers reporting fabrication of magnetic tunnel junctions using graphene between two ferromagnetic metal layers have demonstrated, for the first time, the use of graphene as a tunnel barrier—an electrically insulating barrier between two conducting materials through which electrons tunnel quantum mechanically. They accomplished the feat using a fully scalable photolithographic process.
Smooth wrinkles and sharply crumpled regions are familiar motifs in biological and synthetic sheets, such as plant leaves and crushed foils, say physicists at the University of Massachusetts Amherst, but how a featureless sheet develops a complex shape has long remained elusive. Now, the physicists report that they have identified a fundamental mechanism by which such complex patterns emerge spontaneously.
Life would be a lot easier if the surfaces of window panes, corrosion coatings or microfluidic systems in medical labs could keep themselves free of water and other liquids. A new simulation program developed by researchers in Germany can now work out just how such surfaces have to look for a variety of applications.
Joshua Zide has spent nearly a decade engineering nanomaterials using molecular beam epitaxy. His particular area of expertise are metalllic-semiconductor nanocomposite for use in electronics, and he is now working on a variation of epitaxy that he hopes will bring the materials deposition technique to the production line for the first time.