We exploit the'self-organization'of semiconducting nanocrystals by the'Stranski-Krasnov (SK) mode of crystal growth for producing ordered highly dense
or'top-down'methods widely used for the fabrication of nanostructures. Notably electrons in quantum dot structures are confined inside nanometer sized three dimension boxes.
Novel applications of'quantum dots'including lasers biological markers qubits for quantum computing and photovoltaic devices arise from the unique optoelectronic properties of the QDS
This density was one of the critical advances for achieving high efficiency quantum dot based photovoltaic devices says Yamaguchi.
dx. doi. org/10.1143/APEX. 5. 125502 Katsuyoshi Sakamoto Yasunori Kondo Keisuke Uchida and Koichi Yamaguchi Quantum dot density dependence of power conversion
Polymersome magneto-valves for reversible capture and release of nanoparticles. Nature Communications DOI: 10.1038/ncomms601 6
#Fabrication route improves the properties of aluminum-based nanocomposites One challenge in producing strong elastic
and hard-wearing nanocomposites is obtaining an even distribution of the nanoparticles in the metal matrix.
Their technique is a viable new method for manufacturing nanocomposites and has exciting potential for the car space and defense industries.
They then injected a slurry of aluminum oxide nanoparticles into the holes and heated the sheet in an oven.
Placing the nanoparticles in the sheet prior to the friction stir processing step significantly increased the concentration of nanoparticles in the composite.
The team used scanning electron microscopy to check two key properties that influence the strength of nanocomposites.
They first demonstrated that the nanoparticles were dispersed uniformly which means the material has no weak points.
and without the Al2o3 nanoparticles the team showed that the nanoparticles contributed to the reduction in grain size.
The best nanoparticle distribution and smallest aluminum alloy grains were obtained after passing the rotating tool through the sheet four times.
We plan to continue this research to further improve the mechanical and thermal properties as well as the wear resistance of the nanocomposites says Guo.
Scientists use nanoparticles to control growth of materials More information: Guo J. F. Liu J. Sun C. N. Maleksaeedi S. Bi G. et al.
#Gold nanoparticles linked to single stranded-dna DNA create a simple but versatile genetic testing kit Tests for identifying genetic variations among individuals
and elegant nanoprobe for assessing sensitivity to the drug warfarin. To develop the nanoprobe Jackie Ying at the A*STAR Institute of Bioengineering
and Nanotechnology and co-workers in Singapore Taiwan and Japan devised a relatively simple procedure that uses standard laboratory equipment
and can be adapted easily for other genetic tests. Our method is faster more cost-effective
The researchers used gold nanoparticles attached to short sections of DNA that bind to specific complementary sequences of DNA through the base pairing that holds together double-stranded DNA.
These nanoprobes were exposed to fragments of DNA that had been cut out and amplified from a patient's genome.
The nanoprobes are initially pink due to surface plasmonic effects involving ripples of electric charge. When analyzed if the probes do not bind to the DNA fragments they aggregate
Using gold nanoprobes to unlock your genetic profile More information: Zu Y. Tan M.-H. Chowbay B. Lee S. C. Yap H. et al.
Nanoprobe-based genetic testing. Nano Today 9 166#171 (2014. dx. doi. org/10.1016/j. nantod. 2014.04.00
#Researchers uncover properties in nanocomposite oxide ceramics for reactor fuel Nanocomposite oxide ceramics have potential uses as ferroelectrics fast ion conductors
In a nanocomposite the size of each of these grains is on the order of nanometers roughly 1000 times smaller than the width of a human hair.
and radiation damage resistance of oxide nanocomposites by controlling the termination chemistry at the interface.
We believe that this discovery that the interface structure is sensitive to the chemistry of the interface will open the door for new research directions in oxide nanocomposites said Blas Uberuaga lead researcher on the effort.
Gan microstructures and nanostructures are garnering attention within the research community as light-emitting devices because of their variable-color light emission
#Experts create unique nanoparticles for aerospace industry A development of three universities enables improved thermal and electronic properties on devices with nickel-titanium alloys.
Experts collaborated to produce nanoparticles made of a titanium-nickel alloy used in the development of thermal and electrical sensors that control the operation of high-tech devices such as those used in aerospace,
Meanwhile, the team at the UANL manufactured nanoparticles used in the sensors, and after a series of tests confirmed the effectiveness of the titanium-nickel as an electrical and thermal conductor.
With nanoparticles, they produced temperature-sensitive devices that transmit electrical energy to the system but do not cause overheating.
Then nanoparticles were obtained by thermal evaporation techniques where the molecular bonds of the metals degraded as a powder
Besides generating nanoparticles for sensors, another goal of this proyect is to train high level human resources in the areas of metallurgy alloys with shape memory,
nanotechnology and improving infrastructure in order to impact scientific and technological production in both countries. Finally, to test the effectiveness of the material,
and related materials rather than just microscopic flakes as previously was the case greatly expands their promise for nanoelectronic and optoelectronic applications.
Dr Huang and his team published their findings in the latest issue of the journal Nanoscale.
#Nanotubes help healing hearts keep the beat (Phys. org) Carbon nanotubes serve as bridges that allow electrical signals to pass unhindered through new pediatric heart-defect patches invented at Rice university and Texas Children's Hospital.
and chemical engineer and chemist Matteo Pasquali created the patches infused with conductive single-walled carbon nanotubes.
The nanotubes overcome a limitation of current patches in which pore walls hinder the transfer of electrical signals between cardiomyocytes the heart muscle's beating cells
Nanotubes can fix that and Jacot who has a joint appointment at Rice and Texas Children's took advantage of the surrounding collaborative research environment.
We thought nanotubes could be integrated easily. Nanotubes enhance the electrical coupling between cells that invade the patch helping them keep up with the heart's steady beat.
When cells first populate a patch their connections are compared immature with native tissue Jacot said.
but the nanotubes forge a path around the obstacles. Jacot said the relatively low concentration of nanotubes 67 parts per million in the patches that tested best is key.
Earlier attempts to use nanotubes in heart patches employed much higher quantities and different methods of dispersing them.
Jacot's lab found a component they were already using in their patches#chitosan#keeps the nanotubes spread out.
Chitosan is amphiphilic meaning it has hydrophobic and hydrophilic portions so it can associate with nanotubes (which are hydrophobic)
and keep them from clumping. That's what allows us to use much lower concentrations than others have tried.
and get to it with the fewest nanotubes possible he said. We can do this if we control dispersion well and use high-quality nanotubes.
The patches start as a liquid. When nanotubes are added the mixture is shaken through sonication to disperse the tubes
which would otherwise clump due to Van der waals attraction. Clumping may have been an issue for experiments that used higher nanotube concentrations Pasquali said.
The material is spun in a centrifuge to eliminate stray clumps and formed into thin fingernail-sized discs with a biodegradable polycaprolactone backbone that allows the patch to be sutured into place.
As a side benefit nanotubes also make the patches stronger and lower their tendency to swell
Pasquali noted that Rice's nanotechnology expertise and Texas Medical center membership offers great synergy. This is a good example of how it's much better for an application person like Dr. Jacot to work with experts who know how to handle nanotubes rather than trying to go solo as many do said he.
We end up with a much better control of the material. The converse is also true of course
Biocompatible Carbon nanotube#Chitosan Cardiac Scaffold Matching the Electrical conductivity of the Heart. Seokwon Pok Flavia Vitale Shannon L. Eichmann Omar M. Benavides Matteo Pasquali and Jeffrey G Jacot ACS Nano Just Accepted Manuscript DOI:
and better understand the workings of the nanomachines of life, such as ribosomes and DNA polymerases.
Using an optical microstructure and gold nanoparticles, they have amplified the interaction of light with DNA to the extent that they can now track interactions between individual DNA molecule segments.
In cells, nanomachines such as ribosomes and DNA polymerases stitch individual molecules together to form complex biological structures such as proteins and DNA molecules, the repositories of genetic information.
and it can interfere with the function of the biological nanomachines. Although light can be used to detect unlabelled biomolecules,
and gold nanowires approx. 12 nanometres in diameter and 42 nanometres in length. The gold wire is therefore only about one ten-thousandth the thickness of a hair.
The microsphere and nanowire amplify the interaction between light and molecules. With the help of a prism, the researchers shine laser light into the microsphere.
Vollmer and his colleagues therefore fix a nanowire to the surface of the glass bead.
to the nanowire mounted on the microsphere. When a matching, i e. COMPLEMENTARY DNA fragment binds to the"bait"on the nanowire
the wavelength of the light shifts and is amplified by the microsphere and nanowire. This shift can be measured.
Different strand sections can be distinguished by their binding behaviour However, the physicists used a shorter DNA fragment than is usual in similar procedures.
and nanomachines are fleeting. Thanks to the new method, it is now possible to explore such natural kinetics in greater detail,
#Engineers show light can play seesaw at the nanoscale University of Minnesota electrical engineering researchers have developed a unique nanoscale device that for the first time demonstrates mechanical transportation of light.
and will appear in the October issue of Nature Nanotechnology researchers developed a novel nanoscale device that can capture measure
Optomechanical photon shuttling between photonic cavities Nature Nanotechnology (2014) DOI: 10.1038/nnano. 2014.20 0
#A nanosized hydrogen generator (Phys. org) esearchers at the US Department of energy's (DOE) Argonne National Laboratory have created a small scale"hydrogen generator"that uses light
"said Elena Rozhkova, chemist at Argonne's Center for Nanoscale Materials, a DOE Office of Science (Office of Basic energy Sciences) User Facility."
These protons make their way to the platinum nanoparticles which sit on top of the titanium dioxide. Hydrogen is produced by the interaction of the protons
and time-resolved spectroscopy at the Center for Nanoscale Materials verified the movements of the electrons within the system,
"Rozhkova's hydrogen generator proves that nanotechnology, merged with biology, can create new sources of clean energy.
#Nanoribbon film keeps glass ice-free: Team refines deicing film that allows radio frequencies to pass Rice university scientists who created a deicing film for radar domes have refined now the technology to work as a transparent coating for glass.
The material is made of graphene nanoribbons atom-thick strips of carbon created by splitting nanotubes a process also invented by the Tour lab
Last year the Rice group created films of overlapping nanoribbons and polyurethane paint to melt ice on sensitive military radar domes
The new films are between 50 and 200 nanometers thick a human hair is about 50000 nanometers thick
In the previous process the nanoribbons were mixed with polyurethane but testing showed the graphene nanoribbons themselves formed an active network when applied directly to a surface.
He said nanoribbon films also open a path toward embedding electronic circuits in glass that are both optically and RF transparent a
#The future face of molecular electronics The emerging field of molecular electronics could take our definition of portable to the next level enabling the construction of tiny circuits from molecular components.
Picene's sister molecule pentacene has been studied widely because of its high carrier mobilityts ability to quickly transmit electrons a critical property for nanoscale electronics.
The weak interaction is advantageous for molecular electronics applications because the modification of the properties of molecular thin film by the presence of the silver is negligible
For this study scientists looked at a positive electrode made of billions of nanoparticles of lithium iron phosphate.
Previous studies produced conflicting views of how the nanoparticles behaved. To probe further researchers made small coin cell batteries charged them with different levels of current for various periods of time quickly took them apart
We were able to look at thousands of electrode nanoparticles at a time and get snapshots of them at different stages during charging
Analyzing the data using a sophisticated model developed at MIT the researchers discovered that only a small percentage of nanoparticles absorbed and released ions during charging even
#Aligned carbon nanotube/graphene sandwiches By in situ nitrogen doping and structural hybridization of carbon nanotubes (CNTS) and graphene via a two-step chemical vapor deposition (CVD) scientists have fabricated nitrogen-doped aligned carbon nanotube/graphene (N-ACNT/G) sandwiches
with three-dimensional (3d) electron transfer pathways interconnected ion diffusion channels and enhanced interfacial affinity and activity.
CNTS and graphene the most highlighted sp2-bonded carbon nanomaterials over the past decades have attracted enormous attention in the area of energy storage heterogeneous catalysis healthcare environmental protection as well as nanocomposites
However the heteroatom-containing nanocarbon tends to aggregate due to strong Van der waals interactions and large surface area explosion thereby constantly limiting the demonstration of their intrinsic physical properties and performances in as-fabricated materials and practical devices.
The combination of CNTS and graphene into 3d hybrid composites can usually mitigate the self-aggregation
and restacking of nanocarbon materials and also amplify physical properties at macroscale. Up to now several strategies have been explored to fabricate such CNTS/graphene hybrids including post-organization methods
and in situ growth while integration of high-quality CNTS and graphene without barrier layers is still difficult.
A team from Tsinghua University (China) led by Prof. Qiang Zhang and Fei Wei have fabricated now successfully sandwich-like N-ACNT/G hybrids via a two-step catalytic growth on bifunctional natural materials.
Aligned CNTS were intercalated firstly into the interlayer spaces of the layered catalyst embedded with metal nanoparticles (NPS) through a low-temperature (L-T) CVD
and graphene was deposited sequentially onto the surface of lamellar flakes at the bottom of aligned CNTS through a high-temperature (H-T) CVD.
After catalyst removal alternative aligned CNTS and graphene were connected vertically to each other in long-range periodicity thereby forming a sandwich-like structure.
The key issue for the fabrication of the novel N-ACNT/G architecture is that the high-quality aligned CNTS
Org''Thereby the seamless connection of high-quality aligned CNTS and graphene provided 3d electron transfer pathways and interconnected ion diffusion channels.
which was about 65%higher than that of sole aligned CNTS. Even at a high current density of 5. 0 C a reversible capacity of ca. 770 mah g-1 can be achieved.
Zhang elaborated The seamless junction of CVD-grown aligned CNTS and graphene provides rapid electron transfer and mechanical robustness.
It is expected highly that the N-ACNT/G sandwiches hold various potential applications in the area of nanocomposite energy storage environmental protection electronic device as well as healthcare because of their robust hierarchical structure 3d electron transfer
and fabrication strategy is generally applicable we foresee a new branch of material chemistry evolving in the area of advanced hierarchical nanostructures through the 3d topological nanosystems and interfacial modification.
Tang C Zhang Q Zhao MQ Huang JQ Cheng XB Tian GL Peng HJ Wei F. Nitrogen-Doped Aligned Carbon nanotube
Greer's team has developed a method for constructing new structural materials by taking advantage of the unusual properties that solids can have at the nanometer scale,
if you use the concept of the nanoscale to create structures and then use those nanostructures like LEGO to construct larger materials,
you can obtain nearly any set of properties you want. You can create materials by design."
what they call three-dimensional nanolattices that are formed by a repeating nanoscale pattern. After the patterning step,
aluminum oxide), producing hollow-tube alumina structures with walls ranging in thickness from 5 to 60 nanometers and tubes from 450 to 1, 380 nanometers in diameter.
and prodding materials on the nanoscale, they squished, stretched, and otherwise tried to deform the samples to see how they held up.
They found that the alumina structures with a wall thickness of 50 nanometers and a tube diameter of about 1 micron shattered when compressed.
when you reduce these structures down to the point where individual walls are only 10 nanometers thick,
#'Human touch'nanoparticle sensor could improve breast cancer detection (Phys. org) niversity of Nebraska-Lincoln scientists have developed a nanoparticle-based device that emulates human touch
In research funded with a grant from the National institutes of health, Saraf and Nguyen perfected a thin film made of nanoparticles and polymers
#Team uses nanotechnology to help cool electrons with no external sources A team of researchers has discovered a way to cool electrons to#228°C without external means and at room temperature,
The team used a nanoscale structure which consists of a sequential array of a source electrode, a quantum well,
a tunneling barrier, a quantum dot, another tunneling barrier, and a drain electrode to suppress electron excitation
#Molecular self-assembly controls graphene-edge configuration A research team headed by Prof. Patrick Han and Prof.
However on the nanoscale adding fluorine to graphene had been reported to vastly increase the friction experienced
when we tested the friction of these different samples with an atomic force microscope an ultra-sensitive instrument that can measure nanonewton forces.
which at the nanoscale can act like physical roughness in increasing friction. In fluorinated graphene the fluorine atoms do stick up out of the plane of carbon atoms
At the nanoscale Carpick said friction isn't just determined by the placement of atoms
and undoped graphene pieces they were able to form heterojunctions in the nanoribbons thereby fulfilling a basic requirement for electronic current to flow in only one direction
Empa researchers from the nanotech@surfaces laboratory thus developed a method some time ago to synthesise a form of graphene with larger bandgaps by allowing ultra-narrow graphene nanoribbons to grow via molecular self-assembly.
The researchers describe the corresponding heterojunctions in segmented graphene nanoribbons in the recently published issue of Nature Nanotechnology.
Transferring graphene nanoribbons onto other substratesin addition the scientists have solved another key issue for the integration of graphene nanotechnology into conventional semiconductor industry:
In a second paper published in Nature Communications Pascal Ruffieux also from the Empa nanotech@surfaces laboratory
In a paper first published online on Sept. 9 in the journal Nature Chemistry, Mallouk and colleagues at Penn State and the Research center for Exotic Nanocarbons at Shinshu University, Japan, describe a method called intercalation,
A research paper about the new detector was published Sunday September 07 2014 in Nature Nanotechnology.
Nature Nanotechnology dx. doi. org/10.1038/nnano. 2014.18
#First graphene-based flexible display produced A flexible display incorporating graphene in its pixels'electronics has been demonstrated successfully by the Cambridge Graphene Centre and Plastic Logic,
who is also the director of the Nanoelectronics Research Lab at UCSB. Graphene has been used among other things to design FETSEVICES that regulate the flow of electrons through a channel via a vertical electric field directed into the channel by a terminal called a gate.
either by patterning graphene to make nanoribbons or by introducing defects in the graphene layerr using bilayer graphene stacked in a certain pattern that allows band gap opening upon application of a vertical electric fieldor better control and detection of current.
Monolayer or few-layer Mos2 have a key advantage over graphene for designing an FET biosensor:
While one-dimensional materials such as carbon nanotubes and nanowires also allow excellent electrostatics and at the same time possess band gap they are not suitable for low-cost mass production due to their process complexities she said.
At present the scientific community worldwide is actively seeking practical applications of 2d semiconductor materials such as Mos2 nanosheets.
Professor Banerjee and his team have identified a breakthrough application of these nanomaterials and provided new impetus for the development of low-power
and Swiss Federal Institute of technology in Zurich describe a basic model circuit consisting of a silver nanowire and a single-layer flake of molybendum disulfide (Mos2).
We have found that there is pronounced nanoscale light-matter interaction between plasmons and atomically thin material that can be exploited for nanophotonic integrated circuits said Nick Vamivakas assistant professor of quantum optics and quantum physics at the University of Rochester and senior author of the paper.
K. Goodfellow R. Beams C. Chakraborty L. Novotny A n. Vamivakas Integrated nanophotonics based on nanowire plasmons and atomically-thin material Optica Vol. 1 Issue
#Researcher's nanoparticle key to new malaria vaccine A self-assembling nanoparticle designed by a UCONN professor is the key component of a potent new malaria vaccine that is showing promise in early tests.
But a novel protein nanoparticle developed by Peter Burkhard, a professor in the Department of Molecular & Cell biology, in collaboration with David Lanar
The key to the vaccine's success lies in the nanoparticle's perfect icosahedral symmetry (think of the pattern on a soccer ball)
We are able to achieve our high density because of the design of the nanoparticle, which we control."
It took the researchers more than 10 years to finalize the precise assembly of the nanoparticle as the critical carrier of the vaccine
holds the patent on the self-assembling nanoparticle used in the malaria vaccine. Burkhard is also exploring other potential uses for the nanoparticle,
including a vaccine that will fight animal flu and one that will help people with nicotine addiction.
and carrier concentrations with an accurate nanoscale picture of the semiconductor film's microstructure really gives a complete picture of how the device operates and
#Electron microscopes take first measurements of nanoscale chemistry in action (Phys. org) Scientists'underwater cameras got a boost this summer from the Electron microscopy Center at the U s. Department of energy's Argonne National Laboratory.
Along with colleagues at the University of Manchester researchers captured the world's first real-time images and simultaneous chemical analysis of nanostructures while underwater or in solution.
and materials scientists to explore never-before-measured stages of nanoscale chemical processes in materials said Argonne materials scientist Nestor Zaluzec one of the paper's authors.
Understanding how materials grow at the nanoscale level helps scientists tailor them for everything from batteries to solar cells.
and nanoscale for decades but it's usually done with the sample in a vacuum Zaluzec said.
This lets scientists watch as nanostructures grow and change with time during chemical reactions. The team is now working with the manufacturer Protochips Inc. to make this capability available to the scientific community.
The study Real-time imaging and local elemental analysis of nanostructures in liquids was published in the journal Chemical Communications with researchers from the University of Manchester and BP.
Real-time imaging and local elemental analysis of nanostructures in liquids. Edward A. Lewis et al. Chem.
The researchers used a handheld device resembling a laser pointer that can detect Raman nanoprobes with very high accuracy.
These nanoprobes are injected the day prior to the operation and go specifically to tumor cells and not to normal brain cells.
Guiding Brain tumor Resection Using Surface-Enhanced Raman Scattering Nanoparticles and a Hand-held Raman Scanner ACS Nano Article ASAPDOI:
Here we evaluated the ability of a hand-held Raman scanner guided by surface-enhanced Raman scattering (SERS) nanoparticles to identify the microscopic tumor extent in a genetically engineered RCAS/tv-a glioblastoma mouse model.
and correlation with histology showed that SERS nanoparticles accurately outlined the extent of the tumors.
because it uses inert gold#silica SERS nanoparticles and a hand-held Raman scanner that can guide brain tumor resection in the operating room o
a new class of nanoscale materials made in sheets only three atoms thick. The University of Washington researchers have demonstrated that two of these single-layer semiconductor materials can be connected in an atomically seamless fashion known as a heterojunction.
or monolayer, materials molybdenum diselenide and tungsten diselenide that have very similar structures, which was key to creating the composite two-dimensional semiconductor.
"The researchers have demonstrated already that the junction interacts with light much more strongly than the rest of the monolayer,
"Wang is the corresponding author of a paper in Nature Nanotechnology describing this research. The paper is titled"Ultrafast charge transfer in atomically thin Mos2/WS2 heterostructures."
MX2 monolayers consist of a single layer of transition metal atoms, such as molybdenum (Mo) or tungsten (W), sandwiched between two layers of chalcogen atoms,
who is also an investigator with the Kavli Energy Nanosciences Institute (Kavli-ENSI).""For example, the combination of Mos2 and WS2 forms a type-II semiconductor that enables fast charge separation.
#Conductive nanofiber networks for flexible unbreakable and transparent electrodes Transparent conductors are required as electrodes in optoelectronic devices, such as touch panel screens, liquid crystal displays, and solar cells.
Tokyo Institute of technology researchers report the first development of a facile method for the fabrication of flexible and unbreakable transparent electrodes using nanofibers.
Two-dimensional aluminum (Al) nanofiber networks offering transparent conductors were fabricated by simple wet chemical etching of Al metalized polymer films using an electrospun polystyrene nanofiber mask template.
The resulting Al nanowire networksith a width of 500 nm and an area fraction of 22.0%xhibited 80%optical transmittance and sheet resistance of 45 O sq-1
The metallic nanostructures use surface plasmons waves of electrons that flow like a fluid across metal surfaces.
Researchers use aluminum nanostructures for photorealistic printing of plasmonic color palettes More information: Zheng B. Y. Wang Y. Nordlander P. and Halas N. J. 2014) Color-Selective and CMOS-Compatible Photodetection Based on Aluminum Plasmonics.
Overtext Web Module V3.0 Alpha
Copyright Semantic-Knowledge, 1994-2011