#Scientists improve microscopic batteries with homebuilt imaging analysis (Phys. org) In a rare case of having their cake
To see as much detail as possible the team decided to use a set of electron detectors to collect electrons in a wide range of scattering angles an arrangement that gave them plenty of structural information to assemble a clear picture of the battery's interior down to the nanoscale level.
Miniature all-solid-state heterostructure nanowire Li-ion batteries as a tool for engineering and structural diagnostics of nanoscale electrochemical processes.
Nanoscale DOI: 0. 1039/c4nr01666a Aug 15 2014
#Research mimics brain cells to boost memory power RMIT University researchers have brought ultra-fast, nanoscale data storage within striking reach,
using technology that mimics the human brain. The researchers have built a novel nanostructure that offers a new platform for the development of highly stable and reliable nanoscale memory devices.
The pioneering work will feature on a forthcoming cover of materials science journal Advanced Functional Materials (11 november.
Project leader Dr Sharath Sriram, co-leader of the RMIT Functional Materials and Microsystems Research Group, said the nanometer-thin stacked structure was created using thin film, a functional oxide
"The structure we developed could be used for a range of electronic applications from ultrafast memory devices that can be shrunk down to a few nanometers,
#New research points to graphene as a flexible low-cost touchscreen solution New research published today in the journal Advanced Functional Materials suggests that graphene-treated nanowires could soon replace current touchscreen technology
Researchers from the University of Surrey and AMBER the materials science centre based at Trinity college Dublin have demonstrated now how graphene-treated nanowires can be used to produce flexible touchscreens at a fraction of the current cost.
Using a simple scalable and inexpensive method the researchers produced hybrid electrodes the building blocks of touchscreen technology from silver nanowires and graphene.
Lead author Dr Izabela Jurewicz from the University of Surrey commented Our work has cut the amount of expensive nanowires required to build such touchscreens by more than fifty times as well as simplifying the production process.
We achieved this using graphene a material that can conduct electricity and interpret touch commands
Conductive nanofiber networks for flexible unbreakable and transparent electrode e
#Harnessing an unusual'valley'quantum property of electrons Yoshihiro Iwasa and colleagues from the RIKEN Center for Emergent Matter Science the University of Tokyo and Hiroshima University have discovered that ultrathin films of a semiconducting material have properties that form the basis for a new kind of low-power electronics termed'valleytronics'.
In the form of nanowires and nanoparticles it has particular potential for use in the manufacture of solar cells
It had already been demonstrated on nanowires made from one crystalline form of gallium arsenide the cubic so-called zincblende structure that the band gap widens under pressure.
The present research focused instead on nanowires of a less-common crystalline form the hexagonal so-called wurtzite structure.
They discovered the band gap that the electrons need to leap across to also widened although not as much as in the case of the zincblende crystal nanowires.
Significantly they discovered that around 207000 times normal atmospheric pressure (21 gigapascals) the wurtzite gallium arsenide nanowires underwent a structural change that induced a new phase the so-called orthorhombic one
or even a single nanowire and realize much more complex and useful electronic functions through interactions across the phases Goncharov said.
#Controlling photoluminescence with silicon nanophotonics for better devices Silicon nanowires have a great deal of potential in future high-performance electronic sensing and energy devices.
Red photoluminescence has been reported in silicon nanowires but for many applications this hampers device performance. As Tsuyoshi Okuno from the University of Electro-Communications and his colleagues point out in a recent report
Okuno and his colleagues fabricated silicon nanowire arrays by metal-assisted chemical etching an approach that is simple and cost-effective.
They deposited metal nanoparticles on a silicon wafer and etched nanowires using aqueous H2o2. Although the researchers did not have precise control over the nanowire morphology they did observe that higher concentrations of H2o2 led to thicker nanowires.
Photoluminescence studies did not reveal a link between photoluminescence and nanowire diameter or length alone but low aspect ratio nanowires exhibited red photoluminescence.
Further observations of the morphology identified silicon nanocrystals at the nanowire ends which was corroborated by Raman studies of single nanowires.
These nanocrystals disappear on annealing as does the red photoluminescence. The researchers attribute the red photoluminescence to defect states between nanocrystals and surrounding oxide and excitonic transitions.
As the researchers conclude in their report These results of Si nanowire arrays are believed to be useful for future optoelectronic and photovoltaic applications.
Explore further: Mixing silicon with other materials improves the diversity of nanoscale electronic devices More information:
Oda K. Nanai Y. Sato T. Kimura S. & Okuno T. Correlation between photoluminescence and structure in silicon nanowires fabricated by metal-assisted etching.
Physica Status Solidi A 211 (4) 848-855 (2014) DOI: 10.1002/pssa. 20133016 6
#World's smallest reference material is big plus for nanotechnology If it's true that good things come in small packages,
then the National Institute of Standards and Technology (NIST) can now make anyone working with nanoparticles very happy.
NIST recently issued Reference Material (RM) 8027, the smallest known reference material ever created for validating measurements of these man-made, ultrafine particles between 1 and 100 nanometers (billionths of a meter) in size.
RM 8027 consists of five hermetically sealed ampoules containing one milliliter of silicon nanoparticlesll certified to be close to 2 nanometers in diameteruspended in toluene.
To yield the appropriate sizes for the new RM the nanocrystals are etched from a silicon wafer,
separated using ultrasound and then stabilized within an organic shell. Particle size and chemical composition are determined by dynamic light scattering, analytical centrifugation, electron microscopy and inductively coupled plasma mass spectrometry (ICP-MS),
a powerful technique that can measure elements at concentrations as low as several parts per billion."
"For anyone working with nanomaterials at dimensions 5 nanometers or less, our well-characterized nanoparticles can ensure confidence that their measurements are accurate,
"says NIST research chemist Vytas Reipa, leader of the team that developed and qualified RM 8027.
Silicon nanoparticles such as those in RM 8027 are being studied as alternative semiconductor materials for next-generation photovoltaic solar cells and solid-state lighting,
Another potential application comes from the fact that silicon crystals at dimensions of 5 nanometers
silicon nanoparticles may one day serve as easily detectable"tags"for tracking nanosized substances in biological, environmental or other dynamic systems s
#Self-organized indium arsenide quantum dots for solar cells Kouichi Yamaguchi is recognized internationally for his pioneering research on the fabrication and applications of'semiconducting quantum dots'(QDS.
We exploit the'self-organization'of semiconducting nanocrystals by the'Stranski-Krasnov (SK) mode of crystal growth for producing ordered highly dense
and highly uniform quantum dots explains Yamaguchi. Our'bottom-up'approach yields much better results than the conventional photolithographic
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
when irradiated with light or under external electromagnetic fields. Our main interest in QDS is for the fabrication of high efficiency solar cells says Yamaguchi.
This density was one of the critical advances for achieving high efficiency quantum dot based photovoltaic devices says Yamaguchi.
Resonant energy transfer from quantum dots to graphene More information: Edes Saputra Jun Ohta Naoki Kakuda and Koichi Yamaguchi Self-Formation of In-Plane Ultrahigh-Density Inas Quantum dots on Gaassb/Gaas (001) Appl.
Phys. Express 5 125502 (2012. DOI: dx. doi. org/10.1143/APEX. 5. 125502 Katsuyoshi Sakamoto Yasunori Kondo Keisuke Uchida and Koichi Yamaguchi Quantum dot density dependence of power conversion
efficiency of intermediate-band solar cells J. Appl. Phys. 112 124515 (2012
#Magnetic field opens and closes nanovesicle Chemists and physicists of Radboud University managed to open and close nanovesicles using a magnet.
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.
Gallium nitride micro-rods grown on graphene substrates Bendy light-emitting diode (LED) displays and solar cells crafted with inorganic compound semiconductor micro-rods are moving one step closer to reality thanks to graphene and the work of a team of researchers in Korea.
Currently most flexible electronics and optoelectronics devices are fabricated using organic materials. But inorganic compound semiconductors such as gallium nitride (Gan) can provide plenty of advantages over organic materials for use in these devices#including superior optical electrical and mechanical properties.
on graphene to create transferrable LEDS and enable the fabrication of bendable and stretchable devices.
Gan microstructures and nanostructures are garnering attention within the research community as light-emitting devices because of their variable-color light emission
When combined with graphene substrates these microstructures also show excellent tolerance for mechanical deformation. Why choose graphene for substrates?
Ultrathin graphene films consist of weakly bonded layers of hexagonally arranged carbon atoms held together by strong covalent bonds.
This makes graphene an ideal substrate because it provides the desired flexibility with excellent mechanical strength
#and it's also chemically and physically stable at temperatures in excess of 1000#C said Yi.
It's important to note that for the Gan micro-rod growth the very stable and inactive surface of graphene offers a small number of nucleation sites for Gan growth
which would enhance three-dimensional island growth of Gan micro-rods on graphene. To create the actual Gan microstructure LEDS on the graphene substrates the team uses a catalyst-free metal-organic chemical vapor deposition (MOCVD) process they developed back in 2002.
Among the technique's key criteria it's necessary to maintain high crystallinity control over doping formation of heterostructures
and reliability of Gan micro-rod LEDS fabricated on graphene to the test they found that the resulting flexible LEDS showed intense electroluminescence (EL)
By taking advantage of larger-sized graphene films hybrid heterostructures can be used to fabricate various electronics
Scientists grow a new challenger to graphene More information: Growth and characterizations of Gan micro-rods on graphene films for flexible light-emitting diodes by Kunook Chung Hyeonjun Beak Youngbin Tchoe Hongseok Oh Hyobin Yoo Miyoung Kim and Gyu
-Chul Yi APL Materials September 23 2014: scitation. aip. org/content/aip/#/9/10.1063/1. 489478 1
#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,
#Scientists grow a new challenger to graphene A team of researchers from the University of Southampton's Optoelectronics Research Centre (ORC) has developed a new way to fabricate a potential challenger to graphene.
Graphene a single layer of carbon atoms in a honeycomb lattice is increasingly being used in new electronic and mechanical applications such as transistors switches
Now ORC researchers have developed molybdenum di-sulphide (Mos2) a similar material to graphene that shares many of its properties including extraordinary electronic conduction
This new class of thin metal/sulphide materials known as transition metal di-chalcogenides (TMDCS) has become an exciting complimentary material to graphene.
However unlike graphene TMDCS can also emit light allowing applications such as photodetectors and light emitting devices to be manufactured.
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.
Because the toxicity of carbon nanotubes in biological applications remains an open question Pasquali said the fewer one uses the better.
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
and a two-dimensional graphene platform to boost production of the hard-to-make element. The research also unveiled a previously unknown property of graphene.
The two-dimensional chain of carbon atoms not only gives and receives electrons, but can also transfer them into another substance.
"said Elena Rozhkova, chemist at Argonne's Center for Nanoscale Materials, a DOE Office of Science (Office of Basic energy Sciences) User Facility."
in short, a material like graphene. Graphene is a super strong, super light, near totally transparent sheet of carbon atoms and one of the best conductors of electricity ever discovered.
Graphene owes its amazing properties to being two-dimensional.""Graphene not only has all these amazing properties,
but it is also ultra-thin and biologically inert,"said Rozhkova.""Its very presence allowed the other components to self-assemble around it,
which totally changes how the electrons move throughout our system.""Rozhkova's mini-hydrogen generator works like this:
both the br protein and the graphene platform absorb visible light. Electrons from this reaction are transmitted to the titanium dioxide on
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,
Tests also revealed a new quirk of graphene behavior.""The majority of the research out there states that graphene principally conducts
and accepts electrons, "said Argonne postdoctoral researcher Peng Wang.""Our exploration using EPR allowed us to prove, experimentally,
that graphene also injects electrons into other materials.""Rozhkova's hydrogen generator proves that nanotechnology,
merged with biology, can create new sources of clean energy. Her team's discovery may provide future consumers a biologically-inspired alternative to gasoline."
"This research,"Photoinduced Electron Transfer pathways in Hydrogen-Evolving Reduced graphene oxide-Boosted Hybrid Nano-Bio Catalyst,
#Graphene sensor tracks down cancer biomarkers An ultrasensitive biosensor made from the wonder material graphene has been used to detect molecules that indicate an increased risk of developing cancer.
To develop a viable bionsensor the researchers from the University of Swansea had to create patterned graphene devices using a large substrate area
which was not possible using the traditional exfoliation technique where layers of graphene are stripped from graphite.
Instead they grew graphene onto a silicon carbide substrate under extremely high temperatures and low pressure to form the basis of the biosensor.
The researchers then patterned graphene devices using semiconductor processing techniques before attaching a number of bioreceptor molecules to the graphene devices.
In their study the researchers used x-ray photoelectron spectroscopy and Raman spectroscopy to confirm that the bioreceptor molecules had attached to the graphene biosensor once fabricated
When 8-OHDG attached to the bioreceptor molecules on the sensor there was a notable difference in the graphene channel resistance
Results showed that the graphene sensor was capable of detecting 8-OHDG concentrations as low as 0. 1 ng ml-1
The graphene biosensor was also considerably faster at detecting the target molecules completing the analysis in a matter of minutes.
and monitor a whole range of diseases as it is quite simple to substitute the specific receptor molecules on the graphene surface.
Graphene has superb electronic transport properties and has an intrinsically high surface-to-volume ratio
Now that we've created the first proof-of-concept biosensor using epitaxial graphene we will look to investigate a range of different biomarkers associated with different diseases and conditions as well as detecting a number of different biomarkers on the same chip.
On the edge of graphene More information: Generic epitaxial graphene biosensors of ultrasensitive detection of cancer risk biomarker Z Tehrani et al 2014 2d Mater. 1 025004. iopscience. iop. org/2053
-1583/1/2/025004/articl l
#Startup scales up graphene production develops biosensors and supercapacitors An official of a materials technology and manufacturing startup based on a Purdue University innovation says his company is addressing the challenge of scaling graphene production for commercial applications.
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 postprocessing steps to use it in functional applications. He said the company's product development team has developed a way to scale the production of graphene to meet commercial volumes and many different applications.
Our graphene electrodes are created using a roll-to-roll chemical vapor deposition process and then they are combined with other materials utilizing a different roll-to-roll process he said.
We can give the same foundational graphene electrodes entirely different properties utilizing standard or custom materials that we are developing for our own commercial products.
In essence what we've done is developed scalable graphene electrodes that are foundational pieces and can be customized easily to unique customer applications.
Timothy Fisher founder and Chief Technology Officer of Bluevine Graphene Industries developed the technology. He also is the James G. Dwyer Professor of Mechanical engineering at Purdue.
The patented technology has been licensed exclusively to Bluevine Graphene Industries through the Purdue Office of Technology Commercialization.
We're moving up to roll-to-roll large-scale manufacturing capabilities. These roll-to-roll systems allow us to increase output by a thousand-fold over the original research-scale processes Fisher said.
These state-of-the-art systems allow us to leverage the game-changing properties of graphene and in particular our graphene petal technology called Folium#at production scales that provide tremendous pricing advantages.
Bluevine Graphene Industries already is developing and testing two commercial applications for its Folium technology:
biosensors and supercapacitors. Johnson said the company's first-generation glucose monitoring technology could impact the use of traditional testing systems like lancets
which are made with gold and other precious metals. The second-generation technology could allow people to use noninvasive methods to test their glucose levels through saliva tears or urine.
Supercapacitors are Bluevine Graphene Industries'second application under development for its Folium graphene. Johnson said the company's graphene supercapacitors are reaching the energy density of lithium-ion batteries without a similar energy fade over time.
Our graphene-based supercapacitors charge in just a fraction of the time needed to charge lithium-ion batteries.
There are many consumer industrial and military applications he said. Wouldn't it be great if mobile phones could be recharged fully in only a matter of minutes
and quality assurance processes to produce commercial volumes of the Folium graphene. We also are focused on working with potential customers to continue to develop baseline products for both our biosensor
Graphene reinvents the futur t
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