Massachusetts Institute of Technology engineers have created a new polymer film that can generate electricity by drawing on a ubiquitous source: water vapor. The new material changes its shape after absorbing tiny amounts of evaporated water, allowing it to repeatedly curl up and down. Harnessing this continuous motion could drive robotic limbs or generate enough electricity to power micro- and nanoelectronic devices, such as environmental sensors.
Growth of new materials is the cornerstone of materials science. At the same time, the energy crisis has brought the spotlight on synthesis and growth of materials for clean energy technologies. However, researchers in these areas do simply grow materials—they assemble the atoms and molecules that form so-called thin films on various substrates, a complex, time-consuming process. Now, a team of engineers is using microwave energy to assemble atoms into thin films and grow them directly onto a substrate at low temperatures.
A research group at NIST has developed a relatively simple, fast, and effective method of depositing uniform, ultrathin layers of platinum atoms on a surface. The new process exploits an unexpected feature of electrodeposition of platinum—if you drive the reaction much more strongly than usual, a new reaction steps in to shuts down the metal deposition process, allowing an unprecedented level of control of the film thickness.
A sensor invented by Tufts University bioengineers, when attached temporarily to a tooth, could one day help dentists fine-tune treatments for patients with chronic periodontitis, for example, or even provide a window on a patient’s overall health. The thin foil-like sensor is built from gold, silk, and graphite, has a built-in antenna to receive power and signals, and is applied directly to a tooth.
When it comes to imaging, every single photon counts if there is barely any available light. This is the point where the latest technologies often reach their limits. Researchers have now developed a single photon avalanche photodiode that can read individual photons in just a few picoseconds. The speed allows the image sensor to capture high quality images with very low light levels.
New tests of nanostructured material developed by scientists at Rice University and Massachusetts Institute of Technology could lead to better armor against everything from gunfire to micrometeorites. The key, they found, was to use composites made of two or more materials whose stiffness and flexibility are structured in very specific ways—such as in alternating layers just a few nanometers thick.
Oxide catalysts play an integral role in many chemical transformations. Greener, more efficient chemical processes would benefit greatly from solid oxide catalysts that are choosier about their reactants, but achieving this has prove a challenge. Now, a team of researchers have developed a straightforward and generalizable process for making reactant-selective oxide catalysts by encapsulating the particles in a sieve-like film that blocks unwanted reactants.
Stanford University scientists have built the first solar cell made entirely of carbon, a promising alternative to the expensive materials used in photovoltaic devices today. Unlike rigid silicon solar panels that adorn many rooftops, Stanford's thin film prototype is made of carbon materials that can be coated from solution.
By combining ion processing and nanolithography, scientists from Aalto University in Finland and the University of Washington have managed to create complex 3D structures at nanoscale. The breakthrough was made while studying the irregular folding of metallic thin films after they were processed by reactive ion etching. After determining the cause, the researchers realized they could control the bending activity with an ion beam.
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.