Graphene’s exotic properties can be tailored by cutting large sheets down to ribbons of specific lengths and edge configurations. But this “top-down” fabrication approach is not yet practical, because current lithographic techniques always produce defects. Now, scientists from the U.S. and Japan have discovered a new “bottom-up” self-assembly method for producing defect-free graphene nanoribbons with periodic zigzag-edge regions.
If it's true that good things come in small packages, then NIST can now make anyone working with nanoparticles very happy. The institute recently issued Reference Material (RM) 8027, the smallest known reference material ever created for validating measurements of man-made, ultrafine particles between 1 and 100 nm in size.
As tech company LG demonstrated this summer with the unveiling of its 18-in flexible screen, the next generation of roll-up displays is tantalizingly close. Researchers are now reporting a new, inexpensive and simple way to make transparent, flexible transistors that could help bring roll-up smartphones with see-through displays and other bendable gadgets to consumers in just a few years.
A common complaints about solar power is that solar panels are still too expensive. Efforts at making them more efficient or longer-lasting have been limited. A new method developed in Okinawa could solve the expense problem: A hybrid form of deposition is being used to create perovskite solar cells from a mixture of inexpensive organic and inorganic raw materials, eliminating the need for expensive crystallized silicon.
Glenn Johnson, CEO of BlueVine Graphene Industries Inc., said many of the methodologies being utilized to produce graphene today are not easily scalable and require numerous post-processing steps to use it in functional applications. He said his company has developed a way to scale graphene production using a roll-to-roll chemical vapor deposition process.
Many a great idea springs from talks over a cup of coffee. But it’s rare and wonderful when a revelation comes from the cup itself. Rice Univ. theoretical physicist Boris Yakobson, acting upon sudden inspiration at a meeting last year, obtained a couple of spare coffee cups from a server and a pair of scissors and proceeded to lay out—science fair-style—an idea that could have far-reaching implications for the nanotechnology industry.
A new method for controllably constructing precise inter-nanotube junctions and structures in carbon nanotube (CNT) arrays, Northeastern Univ. researchers say, is facile and easily scalable. It will allow them to tailor the physical properties of nanotube networks for use in applications ranging from electronic devices to CNT-reinforced composite materials found in everything from cars to sports equipment.
When it comes to diesel engine catalysts, which are responsible for cleansing exhaust fumes, platinum has unfortunately proved to be the only viable option. This has resulted in material costs alone accounting for half of the price of a diesel catalyst. Researchers in Denmark say they have developed a new way to manufacture catalysts that may result in a 25% reduction in the use of platinum.
Typically a highly conductive material, graphene becomes a semiconductor when prepared as an ultra-narrow ribbon. Recent research has now developed a new method to selectively dope graphene molecules with nitrogen atoms. By seamlessly stringing together doped and undoped graphene pieces, ”heterojunctions” are formed in the nanoribbons, allowing electric current to flow in only one direction when voltage is applied.
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 potentially useful characteristics when fabricated at extremely small scales. But lack of knowledge of how to retain nanoscale properties in materials at larger scales and lack of assembly capabilities for items have prevented us from taking advantage of these nanoscale characteristics. DARPA has created the Atoms to Product (A2P) program to help overcome these challenges.
Scientists in The Netherlands have demonstrated that they can detect extremely small changes in position and forces on very small drums of graphene. Graphene drums have great potential to be used as sensors in devices such as mobile phones. Using their unique mechanical properties, these drums could also act as memory chips in a quantum computer.
Researchers in Europe have succeeded for the first time in growing single-walled carbon nanotubes with only a single, prespecified structure. The nanotubes thereby have identical electronic properties. The decisive trick was producing the carbon nanotube from custom-made organic precursor molecules.
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.
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