Researchers have discussed the merits of surface-stress influence on mechanical properties for decades. Now, a new research platform, called nanomechanical Raman spectroscopy and developed at Purdue Univ., uses a laser to measure the "nanomechanical" properties of tiny structures undergoing stress and heating.
Many common materials exhibit different and...
Scientists in The Netherlands have demonstrated...
A team of materials chemists, polymer scientists, device physicists and others at the Univ. of Massachusetts Amherst report a breakthrough technique for controlling molecular assembly of nanoparticles over multiple length scales that should allow faster, cheaper, more ecologically friendly manufacture of organic photovoltaics and other electronic devices.
For the first time, researchers have succeeded in "growing" single-wall carbon nanotubes (CNT) with a single predefined structure, and hence with identical electronic properties. The method involved self-assembly of tailor-made organic precursor molecules on a platinum surface. In the future, carbon nanotubes of this kind may be used in ultra-sensitive light detectors and ultra-small transistors.
Traditional lithography is based on a simple principle: Oil and water don’t mix. The method, first developed by an actor in Bavaria in 1796, used a smooth piece of limestone on which an oil-based image was drawn and overlayed with gum arabic in water. During printing, the ink was attracted to the oil, and was repelled by the gum.
Most MEMS are made primarily of silicon for reasons of convenience, but they wear out quickly due to friction and they are not biocompatible. Researchers at Argonne National Laboratory and a handful of other institutions around the world have directed their focus on ultrananocrystalline diamond (UNCD), which are smooth and wear-resistant diamond thin films. Recent work opens the door to using diamond for fabricating advanced MEMS devices.
By “drawing” micropatterns on nanomaterials using a focused laser beam, scientists in Singapore have modifed properties of nanomaterials for effective photonic and optoelectronic applications. Their method increased electrical conductivity and photoconductivity of the modified molybdenum disulfide material by more than 10 times and about five times respectively.
A team including scientists from Spain and from IBM Research in Switzerland have published work which describes an extremely simple method to obtain high quality nanographenes from easily available organic compounds. This method is based on the reactivity of a group of molecules named arynes, which can act as "molecular glue" to paste graphene fragments together.
Together with teams from Finland and Japan, physicists from the Univ. of Basel in Switzerland were able to place 20 single bromine atoms on a fully insulated surface at room temperature to form the smallest “Swiss cross” ever created. The effort is a breakthrough because the fabrication of artificial structures on an insulator at room temperature is difficult. It is largest number of atomic manipulations ever achieved at room temperature.
A research group based in Japan has developed a new methodology that can easily and precisely control the timing, structure, and functions in the self-assembly of pi-conjugated molecules, which are an important enabling building block in the field of organic electronics. One of the key steps is keeping these molecules in a liquid form at room temperature.
Robert Wolkow and his team at the Univ. of Alberta are working to engineer atomically precise computing technologies that have practical, real-world applications. In recent research, he and his team observed for the first time how an electrical current flows across the skin of a silicon crystal and also measured electrical resistance as the current moved over a single atomic step.
Using graphene ribbons just several atoms across, a group of researchers at the Univ. of Wisconsin-Milwaukee has found a novel way to “tune” the material, causing the extremely efficient conductor of electricity to act as a semiconductor. By imaging the ribbons with scanning-tunneling microscopy, researchers have confirmed how narrow the ribbon width must be. Achieving less than 10 nm in width is a big challenge.
An international team of physicists including researchers from the U.S. Naval Research Laboratory has used a scanning tunneling microscope to create quantum dots with identical, deterministic sizes. The perfect reproducibility of these dots opens the door to quantum dot architectures completely free of uncontrolled variations, an important goal for technologies from nanophotonics to quantum information processing.
You wouldn’t think that mechanical force could process nanoparticles more subtly than the most advanced chemistry. But researchers at Sandia National Laboratories have created a newly patented and original method that uses simple pressure to produce finer and cleaner results in forming silver nanostructures than do chemical methods, which are not only inflexible in their results but leave harmful byproducts.
An international team has developed an elegant method for producing self-organized and functionalized carbon nanolayers and equipping them chemically with a range of functions. The effort depended on the development of a special compound, the molecules of which were aligned perfectly in parallel to each other in a single self-organized layer, like the bristles on a brush.
According to researchers, a simple, scalable method of making strong, stretchable graphene oxide fibers that are easily scrolled into yarns and have strengths approaching that of Kevlar is possible. An international collaboration has recently produced graphene oxide yarn fibers much stronger than other carbon fibers.
A proposed hybrid quantum processor for a future quantum computer uses trapped atoms as the memory and superconducting qubits as the processor. The concept requires, however, an optical trap that is able to work well with superconductors, which don’t like magnetic fields or high optical power. Joint Quantum Institute scientists believe they’ve developed an effective method for creating these ultra-high transmission optical nanofibers.
Titanium dioxide nanoparticles show great promise as optical encapsulants or fillers for tunable refractive index coatings. However, they've been largely shunned because they’ve been difficult and expensive to make. Scientists at Sandia National Laboratories have now come up with an inexpensive way to synthesize properly sized titanium dioxide nanoparticles and is seeking partners who can demonstrate the process at industrial scale.
Engineers at Oregon State University have successfully shown that a continuous flow reactor can produce high-quality nanoparticles by using microwave-assisted heating. This is essentially the same force that heats up leftover food with such efficiency, but instead of warming up yesterday’s pizza, this concept may change the production of cell phones and televisions or improve solar energy systems.
The days of self-assembling nanoparticles taking hours to form a film over a microscopic-sized wafer are over. Researchers with Lawrence Berkeley National Laboratory have devised a technique whereby self-assembling nanoparticle arrays can form a highly ordered thin film over macroscopic distances in one minute.
A route for constructing protein nanomachines engineered for specific applications may now be closer to reality. Recent research has described the development of new Rosetta software that enables the design of protein nanomaterials composed of multiple copies of distinct protein subunits, which arrange themselves into higher order, symmetrical architectures. It has been used to create a nanocage, built by itself from engineered components.
Haydale, a U.K.-based developer of a unique plasma functionalization process for nanomaterials, has announced the publication of research showing its functionalized graphene nanoplatelets significantly improve the nanoscale reinforcement of resin. The report states a greater than two times increase in tensile strength and modulus of an epoxy composite using this technology.
A porous material invented by the Rice Univ. lab of chemist James Tour sequesters carbon dioxide, a greenhouse gas, at ambient temperature with pressure provided by the wellhead and lets it go once the pressure is released. The material shows promise to replace more costly and energy-intensive processes.
Imagine a tower that builds itself into the desired structure only by choosing the appropriate bricks. Absurd, but in the nano world self-assembly is now a common practice for forming structures. Researchers in Austria have been investigating how they can control the ordering of self-assembling structures and discovered how to switch the assembly process on and off.
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.
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.
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