Defect-free nanowires with diameters in the range of 100 nm hold significant promise for numerous in-demand applications. That promise can't be realized, however, unless the wires can be fabricated in large uniform arrays using methods compatible with high-volume manufacture. To date, that has not been possible for arbitrary spacings in ultra-high vacuum growth.
Researchers from North Carolina State Univ. have developed a new lithography technique that uses...
A potential path to identify imperfections and improve the quality of nanomaterials for use in...
What began as research into a method to...
Techniques for self-assembling of molecules have grown increasingly sophisticated, but biological structures remain a challenge. Recently, scientists have used self-assembly under controlled conditions to create a membrane consisting of layers with distinctly different structures. At the Advanced Photon Source, the team has studied the structures and how they form, paving the way for hierarchical structures with biomedical applications.
The trend toward energy self-sufficient probes and ever smaller mobile electronics systems continues, and are used to monitor the status of the engines on airplanes, or for medical implants. They gather the energy they need for this from their immediate environment, such as vibrations. Fraunhofer Institute researchers have developed a process for the economical production of piezoelectric materials that supply this type of energy.
A few short years ago, the idea of a practical manufacturing process based on getting molecules to organize themselves in useful nanoscale shapes seemed far-fetched. Recent work at NIST, Massachusetts Institute of Technology and IBM Almaden Research Center suggest this capability isn’t far off, however, by demonstrating self-assembly of thin films on a polymer template that creates precise rows just 10 nm wide.
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.
Researchers in Japan have developed a new yet simple technique called "diffusion driven layer-by-layer assembly" to construct graphene into porous 3-D structures for applications in devices such as batteries and supercapacitors. The new method borrowed a principle from polymer chemistry, known as interfacial complexation, to allow graphene oxide to form a stable composite layer with an oppositely charged polymer.
Researchers at Japan’s National Institute of Advanced Industrial Science and Technology have synthesized an atomic chain in which two elements, cesium and iodine, are aligned alternately inside a carbon nanotube. Analyzed using electron microscopy and spectroscopy, the invention could shed light on the adsorption mechanisms of radioactive elements.
Arrays of tiny conical tips that eject ionized materials are being made at the Massachusetts Institute of Technology. The technology, which harnesses electrostatic forces, has a range of promising applications, such as spinning out nanofibers for use in “smart” textiles or propulsion systems for fist-sized “nanosatellites.” The latest prototype array that generates 10 times the ion current per emitter that previous arrays did.
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.
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