#Uniform nanowire arrays for science and manufacturing Defect-free nanowires with diameters in the range of 100 nanometers (nm) hold significant promise for numerous in demand applications including printable
Reproducible synthesis of gallium nitride nanowires with controlled size and location on silicon substrates. The result was achieved by improving selective wire-growth processes to produce one nanowire of controlled diameter per mask-grid opening over a range of diameters from 100 nm to 200 nm.
Ordered arrays with a variety of spacings were fabricated. In the near term the research will be used to create a wafer-scale arrays of probes for devices that examine the surface
and near-surface properties of materials to optimize nanowire LEDS and to produce nanowires with controlled diameter for a collaborative project involving printable transistors for millimeter-wave reconfigurable antennae e
#Designing complex structures beyond the capabilities of conventional lithography Gold nanoparticles smaller than 10 nanometers spontaneously self-organize in entirely new ways
#Nanotubes may restore sight to blind retinas The aging process affects everything from cardiovascular function to memory to sexuality.
The researchers combined semiconductor nanorods and carbon nanotubes to create a wireless light-sensitive flexible film that could potentially replace a damaged retina.
or older who have damage to a specific part of the retina will stand to benefit from the nanotube device
We hope our carbon nanotube and semiconductor nanorod film will serve as a compact replacement for damaged retinas.
We are still far away from actually replacing the damaged retina said Dr. Bareket. But we have demonstrated now that this new material stimulates neurons efficiently and wirelessly with light.
Specifically when a current is passed through the nanopore as the DNA passes through it causes a spike in the current unique to each chemical base (A c T or G) within the DNA molecule.
We have created possibly the smallest-ever stereoscopic images using pixels formed from plasmonic nanostructures Yang told Phys. org.
metal nanostructures can scatter different wavelengths (colors) of light due to the fact that the tiny nanostructures themselves resonate at different wavelengths.
If a nanostructure is circular its resonance is polarization-independent because the diameter of the circle is the same from all directions.
However if a nanostructure is biaxial (such as an ellipse or rectangle) its resonance will depend on the polarization of the incident light.
For example nanostructures that have circularly asymmetric shapes could have more than two polarization-dependent resonances due to the additional circularly polarized dimension.
Silver nanowire ink which is highly conductive and stable offers a more practical solution. Hu's team wanted to develop a way to print it directly on paper to make a sensor that could respond to touch or specific molecules such as glucose.
Direct Writing on Paper of Foldable Capacitive Touch Pads with Silver nanowire Inks ACS Appl. Mater.
10.1021/am506987w Abstractpaper-based capacitive touch pads can be fabricated utilizing high-concentration silver nanowire inks needle-printed directly onto paper substrates through a 2d programmable platform.
Post deposition silver nanowire tracks can be sintered photonically using a camera flash to reduce sheet resistance similar to thermal sintering approaches.
Touch pad sensors on a variety of paper substrates can be achieved with optimized silver nanowire tracks.
#New nanocomposites for aerospace and automotive industries The Center for Research in Advanced Materials (CIMAV) has developed reinforced graphite nanoplatelets seeking to improve the performance of solar cell materials.
These polymer-based nanocomposites are reinforced with graphite nanoplatelets for use in industry. Nanocomposites are formed by two
or more phases in this case by reinforced graphite nanoplatelets. The sectors focused on the use of these nanomaterials are diverse;
Additionally nanocomposite materials are used already in fenders and panels in the automotive and textile industry.
The development of nanocomposites in this research center is an opportunity for different industry sectors; graphite nanoplatelets give added value to the product as they improve its mechanical thermal and electrical properties.
and the use of nanocomposites is an opportunity to improve the product. Even some of the companies we have worked with mentioned in several forums that they have had a good response in the use of these nanomaterials.
She also affirms that the nanocomposites Laboratory in Monterey has achieved success but recognizes that they need to engage with sectors such as aeronautics among other areas.
in addition to companies in the northern state of Nuevo Leon there are companies in other states that have shown interest in polymer nanocomposites;
This is because each nanocomposite is a material that has two or more constituents in this case the polymer and a nano-sized reinforcing material:
#Graphene/nanotube hybrid benefits flexible solar cells Rice university scientists have invented a novel cathode that may make cheap, flexible dye-sensitized solar cells practical.
from nanotubes that are bonded seamlessly to graphene and replaces the expensive and brittle platinum-based materials often used in earlier versions.
"The breakthrough extends a stream of nanotechnology research at Rice that began with chemist Robert Hauge's 2009 invention of a"flying carpet"technique to grow very long bundles of aligned carbon nanotubes.
In his process, the nanotubes remained attached to the surface substrate but pushed the catalyst up as they grew.
The graphene/nanotube hybrid came along two years ago. Dubbed"James'bond"in honor of its inventor, Rice chemist James Tour, the hybrid features a seamless transition from graphene to nanotube.
The graphene base is grown via chemical vapor deposition and a catalyst is arranged in a pattern on top.
which lifts off and allows the new nanotubes to grow. When the nanotubes stop growing,
the remaining catalyst (the"carpet")acts as a cap and keeps the nanotubes from tangling.
The hybrid material solves two issues that have held back commercial application of dye-sensitized solar cells,
First, the graphene and nanotubes are grown directly onto the nickel substrate that serves as an electrode,
With no interruption in the atomic bonds between nanotubes and graphene, the material's entire area, inside and out, becomes one large surface.
Lou's lab built and tested solar cells with nanotube forests of varying lengths The shortest,
Other nanotube samples were grown for an hour and measured about 100-150 microns. When combined with an iodide salt-based electrolyte and an anode of flexible indium tin oxide,
Tests found that solar cells made from the longest nanotubes produced the best results and topped out at nearly 18 milliamps of current per square centimeter
"We're demonstrating all these carbon nanostructures can be used in real applications, "he said
#Bio-inspired bleeding control: Researchers synthesize platelet-like nanoparticles that can do more than clot blood (Phys. org) Stanching the free flow of blood from an injury remains a holy grail of clinical medicine.
Researchers at the University of Pennsylvania have engineered a nanowire system that could pave the way for this ability,
the researchers needed a way to amplify the intensity of a light wave as it passed through a cadmium sulfide nanowire.
partially wrapping the nanowire in a silver shell that acts like an echo chamber. Agarwal's group had employed a similar design before in an effort to create photonic devices that could switch on and off very rapidly.
but, by changing the polarization of the light as it entered the nanowire, the researchers were able to better confine it to the frequency-altering, nonlinear part of the device:
the nanowire core.""By engineering the structure so that light is contained mostly within the cadmium sulfide rather than at the interface between it and the silver shell,
which can be done by altering the size of the nanowire and the shell.""Most important,
This flexible new material which the group has identified as a conductive polymer nanocomposite is the latest expression of the ongoing research in Drexel's Department of Materials science and engineering on a family of composite two-dimensional materials called MXENES.
To produce the flexible conductive polymer nanocomposite the researchers intercalated the titanium carbide MXENE with polyvinyl alcohol (PVA)- a polymer widely used as the paper adhesive known as school
This leads to a nanocomposite with a unique combination of properties said Gogotsi. The results of both sets of MXENE testing were published recently in the Proceedings of the National Academy of Sciences.
We have shown that the volumetric capacitance of an MXENE-polymer nanocomposite can be compared much higher to conventional carbon-based electrodes
The testing also revealed hydrophilic properties of the nanocomposite which means that it could have uses in water treatment systems such as membrane for water purification
These characteristics mark the trail heads of a variety of paths for research on this nanocomposite material for applications from flexible armor to aerospace components.
and polymer will affect the properties of the resulting nanocomposite and also exploring other MXENES and stronger and tougher polymers for structural applications.
The structure is called a nanopore: a tiny hole in a ceramic sheet that holds electrolyte to carry the electrical charge between nanotube electrodes at either end.
The existing device is a test but the bitsy battery performs well. First author Chanyuan Liu a graduate student in materials science & engineering says that it can be charged fully in 12 minutes
Many millions of these nanopores can be crammed into one larger battery the size of a postage stamp.
because each nanopore is shaped just like the others which allows them to pack the tiny thin batteries together efficiently.
Coauthor Eleanor Gillette's modeling shows that the unique design of the nanopore battery is responsible for its success. The space inside the holes is so small that the space they take up all added together would be no more than a grain of sand.
#Team grows uniform nanowires A researcher from Missouri University of Science and Technology has developed a new way to grow nanowire arrays with a determined diameter length and uniform consistency.
This approach to growing nanomaterials will improve the efficiency of various devices including solar cells and fuel cells.
These semiconducting nanowires could also replace thin films that cover today's solar panels. Current panels can process only 20 percent of the solar energy they take in.
By applying the nanowires the surface area of the panels would increase and allow more efficient solar energy capture and conversion.
In fuel cells these nanowire arrays can be used to lower production expenses by relying on more cost-efficient catalysts.
or outperform the current use of platinum and show that these nanowire arrays are better catalysts for the oxygen reduction reactions in the cells says Dr. Manashi Nath assistant professor of chemistry at Missouri S&t.
The nanowires which are grown on patterned nanoelectrodes are visible only through an electron microscope. Nath creates the nanowire arrays through a process that she calls confined electrodeposition on lithographically patterned nanoelectrodes.
To grow the nanowires Nath writes an image file that creates a pattern for the shape
and size she wants to produce. Using electron beam lithography she then stamps the pattern onto a polymer matrix
and the nanowires are grown by applying electric current through electrodeposition. Nath grows the nanowires in a parallel pattern
which resembles a series of nails protruding from a piece of lumber. One end is held secure to a metal conductor like copper
To increase the nanowires'surface area Nath can make them hollow in the middle much like carbon nanotubes found in optics and electronics.
The nanowires allow current to travel through them. The polymer which is nonconductive can be removed to allow the wires to stand freely
one-step process for producing these nanopores in a graphene membrane using the photothermal properties of gold nanorods."
which a hot spot on a graphene membrane formed a nanopore with a self-integrated optical antenna.
The hot spot was created by photon-to-heat conversion of a gold nanorod.""We believe our approach opens new avenues for simultaneous electrical and optical nanopore DNA sequencing
and for regulating DNA translocation,"says Zettl, who is also a member of the Kavli Energy Nanoscience Institute (Kavli ENSI).
Nanopore sequencing of DNA, in which DNA strands are threaded through nanoscale pores and read one letter at a time,
Under today's technology, the DNA letters are"read"by an electrical current passing through nanopores fabricated on a silicon chip.
Trying to read electrical signals from DNA passing through thousands of nanopores at once, however, can result in major bottlenecks.
"Direct and enhanced optical signals are obtained at the junction of a nanopore and its optical antenna,"says Lee."
"Simultaneously correlating this optical signal with the electrical signal from conventional nanopore sequencing provides an added dimension that would be an enormous advantage for high-throughput DNA readout."
The dimensions of the nanopores and the optical characteristics of the plasmonic antenna are tunable, with the antenna functioning as both optical signal transducer and enhancer.
so that each base-pair fluoresces at a signature intensity as it passes through the junction of the nanopore and its optical antenna."
Adrian Bachtold, together with Marc Dykman (Michigan University), report on an experiment in which a carbon nanotube mechanical resonator exhibits quality factors of up to 5 million,
30 times better than the best quality factors measured in nanotubes to date. Imagine that the host of a dinner party tries to get his guests'attention by giving a single tap of his oyster spoon on his crystal glass.
Nowadays, carbon nanotube mechanical resonators are in demand because of their extremely small size and their outstanding capability of sensing objects at the nanoscale.
Like a guitar string or a tightrope, a carbon nanotube resonator consists of a tiny, vibrating bridge-like (string) structure with typical dimensions of 1#m in length and 1nm in diameter.
and because of this trend it was unthinkable that nanotubes could exhibit giant quality factors. The giant quality factors that ICFO researchers have measured have not been observed before in nanotube resonators mainly
because their vibrational states are extremely fragile and easily perturbed when measured. The values detected by the team of scientists was achieved through the use of an ultra-clean nanotube at cryostat temperatures of 30mk(-273.12 Celsius-colder than the temperature of outerspace!
and by employing an ultra-low noise method to detect minuscule vibrations quickly while reducing as much as possible the electrostatic noise.
since"nanotube resonators are enormously sensitive to surrounding electrical charges that fluctuate constantly. This stormy environment strongly affects our ability to capture the intrinsic behavior of nanotube resonators.
For this reason, we had to take a very large number of snapshots of the nanotube's mechanical behavior.
Only a few of these snapshots captured the intrinsic nature of the nanotube's dynamics, when the storm momentarily relented.
During these short quiet moments, the nanotube revealed its ultra-high quality factor to us"."With the discovery of such high quality factors from this study, ICFO scientists have opened a whole new realm of possibilities for sensing applications,
and quantum experiments. For instance, nanotube resonators might be used to detect individual nuclear spins, which would be an important step towards magnetic resonance imaging (MRI) with a spatial resolution at the atomic level.
For the moment, Adrian Bachtold comments that"achieving MRI at the atomic level would be fantastic. But, for this, we would first have to solve various technological problems that are extremely challenging. n
#Method for symmetry-breaking in feedback-driven self-assembly of optical metamaterials (Phys. org) If you can uniformly break the symmetry of nanorod pairs in a colloidal solution you're a step ahead of the game toward achieving new and exciting metamaterial properties.
This led the group to produce nanostructures that have historically been considered impossible to assemble. The widely used method of metamaterial synthesis is top-down fabrication such as electron beam
Starting with a solution of colloidal nanorods Yang and Ni built on the common self-assembly technique used to build nanoparticles.
The desired product when synthesizing colloidal gold nanorods which are stabilized during growth to obtain preferential bonding along longitudinal facets is pairs of rods
You have a pair of nanorods with no shift at all relative to one another; or a pair that are shifted too much;
This allowed them to separate out the undesired resonances indicating nanorod pairs that are shifted not the desired amount
we use the material's own properties to drive nanostructure formation in solution. This has the intrinsic value of making many structures in one batch.
The unique feedback mechanism leads to precisely controlled nanostructures with beyond conventional symmetries and functionalities.
#Better bomb-sniffing technology with new detector material University of Utah engineers have developed a new type of carbon nanotube material for handheld sensors that will be quicker
A carbon nanotube is a cylindrical material that is a hexagonal or six-sided array of carbon atoms rolled up into a tube.
Carbon nanotubes are known for their strength and high electrical conductivity and are used in products from baseball bats and other sports equipment to lithium-ion batteries and touchscreen computer displays.
The new kind of nanotubes also could lead to flexible solar panels that can be rolled up and stored or even"painted"on clothing such as a jacket,
Zang and his team found a way to break up bundles of the carbon nanotubes with a polymer
they alter the electrical current through the nanotube materials, signaling the presence of any of those substances,
and monitor the current through the nanotube,"says Zang, a professor with USTAR, the Utah Science Technology and Research economic development initiative."
or toxic chemicals caught by the nanotube, you will see an increase or decrease in the current."
"By modifying the surface of the nanotubes with a polymer, the material can be tuned to detect any of more than a dozen explosives,
the Utah carbon nanotube technology has four advantages s
#A quantum leap in nanoparticle efficiency (Phys. org) New research has unlocked the secrets of efficiency in nanomaterials that is materials with very tiny particles
Using powerful supercomputers researchers at UWA discovered that graphene nanoflakes can significantly enhance the rates of a range of chemical reactions.
and extend the scope of the study to'infinite'graphene sheets rather than graphene nanoflakes he said d
#Researchers patent a nanofluid that improves heat conductivity Researchers at the Universitat Jaume I (UJI) have developed
and patented a nanofluid improving thermal conductivity at temperatures up to 400°C without assuming an increase in costs
The nanofluid developed by the Multiphase Fluids research group at the UJI is the first capable of working at high temperatures (up to 400°C
The cost of this new nanofluid (to which nanoparticles are added in order to enhance and improve heat conductivity) is similar to that of the base fluid,
after testing the thermal properties of the nanofluid and patenting this new technology, the research group has started the phase of searching industrial partners
either to transfer the nanofluid over to them or with whom applications can be researched jointly and developed.
Finally, Juliá notes that the method employed to produce the nanofluid is easily scalable to the industrial level,
the nanofluid developed is based on a heat transfer oil (diphenyl/diphenyl oxide) that is widely used in industry,
The National Science Foundation (NSF)- funded scientist theorized correctly that he could adapt it to separate carbon nanotubes rolled sheets of graphene (a single atomic layer of hexagonally bonded carbon atoms) long recognized for their potential applications in computers
The carbon nanotubes separation process which Hersam developed begins with a centrifuge tube. Into that we load a water based solution and introduce an additive
We then load the carbon nanotubes and put it into the centrifuge which drives the nanotubes through the gradient.
The nanotubes move through the gradient until their density matches that of the gradient. The result is that the nanotubes form separated bands in the centrifuge tube by density.
Since the density of the nanotube is a function of its diameter this method allows separation by diameter.
One property that distinguishes these materials from traditional semiconductors like silicon is that they are mechanically flexible.
Carbon nanotubes are highly resilient Hersam says. That allows us to integrate electronics on flexible substrates like clothing shoes and wrist bands for real time monitoring of biomedical diagnostics and athletic performance.
These materials have the right combination of properties to realize wearable electronics. He and his colleagues also are working on energy technologies such as solar cells
Breakthrough for carbon nanotube solar cell l
#See-through one-atom-thick carbon electrodes powerful tool to study brain disorders Researchers from the Perelman School of medicine and School of engineering at the University of Pennsylvania and The Children's Hospital of Philadelphia have used graphene
The Center for Neuroengineering and Therapeutics (CNT) under the leadership of senior author Brian Litt Phd has solved this problem with the development of a completely transparent graphene microelectrode that allows for simultaneous optical imaging
Kuzum emphasizes that the transparent graphene microelectrode technology was achieved through an interdisciplinary effort of CNT and the departments of Neuroscience Pediatrics and Materials science at Penn and the division of Neurology at CHOP.
The combination of nanocarbon and sulfur is effective at overcoming the insulating nature of sulfur for lithium sulfur batteries."
"Due to excellent electrical conductivity, mechanical strength and chemical stability, nanocarbon materials have played an essential role in the area of advanced energy storage,
Recently, scientists from Tsinghua University have created a freestanding carbon nanotube paper electrode with high sulfur loading for lithium-sulfur batteries.
"We select carbon nanotube (CNT) as the building block",Qiang told Phys. org, "CNTS are one of the most efficient and effective conductive fillers for electrode.
We selected short multi-walled CNTS (MWCNTS) with lengths of 10-50 m as the shortrange electrical conductive network to support sulfur,
as well as super long CNTS with lengths of 1000-2000 m from vertically aligned CNTS (VACNTS) as both long-range conductive networks and inter-penetrated binders for the hierarchical freestanding paper electrode.""
""We develop a bottom-up routine in which sulfur was dispersed firstly well into the MWCNT network to obtain MWCNT@S building blocks
and then MWCNT@S and VACNTS were assembled into macro-CNT-S films via the dispersion in ethanol followed by vacuum filtration",Zhe Yuan,
"Such sulfur electrodes with hierarchical CNT scaffolds can accommodate over 5 to 10 times the sulfur species compared with conventional electrodes on metal foil current collectors
"The areal capacity can be increased further to 15.1 mah cm-2 by stacking three CNT-S paper electrodes, with an areal sulfur loading of 17.3 mg cm-2 as the cathode in a Li
which is also favorable for graphene, CNT-graphene, CNTMETAL oxide based flexible electrodes, "Qiang said."
and edge configurations scientists have theorized that nanoribbons with zigzag edges are the most magnetic making them suitable for spintronics applications.
This allows the scientists to control the nanoribbons'length edge configuration and location on the substrate.
Paul Weiss distinguished professor of chemistry and biochemistry and a member of UCLA's California Nanosystems Institute developed the method for producing the nanoribbons with Patrick Han and Taro Hitosugi professors at the Advanced Institute
Brighter new energy saving flat panel lights based on carbon nanotubes Even as the 2014 Nobel prize in Physics has enshrined light emitting diodes (LEDS) as the single most significant and disruptive energy-efficient lighting solution of today scientists
Electronics based on carbon especially carbon nanotubes (CNTS) are emerging as successors to silicon for making semiconductor materials.
Scientists from Tohoku University in Japan have developed a new type of energy-efficient flat light source based on carbon nanotubes with very low power consumption of around 0. 1 Watt for every hour's operation
and optimization of the device which is based on a phosphor screen and single-walled carbon nanotubes as electrodes in a diode structure.
They assembled the device from a mixture liquid containing highly crystalline single-walled carbon nanotubes dispersed in an organic solvent mixed with a soap-like chemical known as a surfactant.
The new devices have luminescence systems that function more like cathode ray tubes with carbon nanotubes acting as cathodes
Under a strong electric field the cathode emits tight high-speed beams of electrons through its sharp nanotube tips a phenomenon called field emission.
We have found that a cathode with highly crystalline single-walled carbon nanotubes and an anode with the improved phosphor screen in our diode structure obtained no flicker field emission current and good brightness homogeneity Shimoi said.
In recent years carbon nanotubes have emerged as a promising material of electron field emitters owing to their nanoscale needle shape and extraordinary properties of chemical stability thermal conductivity and mechanical strength.
Highly crystalline single-walled carbon nanotubes (HCSWCNT) have nearly zero defects in the carbon network on the surface Shimoi explained.
The resistance of cathode electrode with highly crystalline single-walled carbon nanotube is very low. Thus the new flat-panel device has compared smaller energy loss with other current lighting devices
Many researchers have attempted to construct light sources with carbon nanotubes as field emitter Shimoi said. But nobody has developed an equivalent and simpler lighting device.
It is this ability to design arbitrary nanostructures using DNA manipulation that inspired the Wyss team to envision using these DNA structures as practical foundries or molds for inorganic substances.
and testing them on skin we have shown that positively charged nanorod shaped nanoparticles are two to six times more effective at penetrating skin than others says lead author Dr Antonios Kanaras.
in order to create nanostructures and to'draw'substances onto nano-sized regions. The latter is called'nanolithography 'and was used the technique by Professor Evans and his team in this research.
spinning out nanofibers for use in water filters body armor and smart textiles; or propulsion systems for fist-sized nanosatellites.
But in the new work they instead used carbon nanotubes atom-thick sheets of carbon rolled into cylinders grown on the slopes of the emitters like trees on a mountainside.
and height of the nanotubes the researchers were able to achieve a fluid flow that enabled an operating ion current at very near the theoretical limit.
To control the nanotubes'growth the researchers first cover the emitter array with an ultrathin catalyst film
The nanotubes grow up under the catalyst particles which sit atop them until the catalyst degrades.
Using their nanotube forest they're able to get the devices to operate in pure ion mode
Overtext Web Module V3.0 Alpha
Copyright Semantic-Knowledge, 1994-2011