#Nanoparticles break the symmetry of light How can a beam of light tell the difference between left and right?
Gold nanoparticles on Glass fibres When a particle absorbs and emits light, this light is emitted not just into one direction."
His team has succeeded now in breaking this symmetry of emission using gold nanoparticles coupled to ultra-thin glass fibres.
This effect has now been demonstrated using a single gold nanoparticle on a glass fibre. The fibre is 250 times thinner than a human hair;
A group of researchers from the Institute of Bioengineering and Nanotechnology (IBN) of A*STAR has taken the health benefits of green tea to the next level by using one of its ingredients to develop a drug delivery system
Using EGCG IBN researchers have engineered successfully nanocarriers that can deliver drugs and kill cancer cells more efficiently.
Their work was published recently in the leading journal Nature Nanotechnology. The numerous health benefits of green tea have inspired us to utilize it in drug delivery systems.
Our green tea nanocarrier not only delivered protein drugs more effectively to the cancer cells, the combination of carrier and drug also dramatically reduced tumor growth compared with the drug alone.
This is an exciting breakthrough in nanomedicine said IBN Executive director Professor Jackie Y. Ying. A key challenge in chemotherapy is ensuring that the drugs are delivered only to the tumor
To solve this problem IBN has designed a therapeutic nanocarrier for drug delivery using novel compounds derived from EGCG.
Micellar nanocomplexes of less than 100 nanometers in dimension are formed from the OEGCG core and PEG-EGCG shell protecting the protein drug from rapid proteolysis
Using the new nanocarrier twice as much drug accumulated in the cancer cells indicating an improved tumor targeting ability.
IBN has filed a patent on their green tea nanocarrier and is developing this technology for clinical applications.
#Arrays of tiny conical tips that eject ionized materials could fabricate nanoscale devices cheaply Luis Fernando Velsquez-Garca's group at MIT's Microsystems Technology Laboratories (MTL) develops dense arrays
depositing or etching features onto nanoscale mechanical devices; spinning out nanofibers for use in water filters body armor and smart textiles;
or propulsion systems for fist-sized nanosatellites. In the latest issue of the IEEE Journal of Microelectromechanical systems Velsquez-Garca his graduate students Eric Heubel and Philip Ponce de Leon and Frances Hill a postdoc in his group describe a new prototype
array that generates 10 times the ion current per emitter that previous arrays did. Ion current is a measure of the charge carried by moving ions
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.
That's crucial for nanofabrication applications in which the depth of an etch or the height of deposits must be consistent across an entire chip.
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.
The emitters like most nanoscale silicon devices were produced through photolithography a process in which patterns are transferred optically to layers of materials deposited on silicon wafers;
Velsquez-Garca believes that using arrays of emitters to produce nanodevices could have several advantages over photolithography the technique that produces the arrays themselves.
and don't require a vacuum chamber the arrays could deposit materials that can't withstand the extreme conditions of many micro-and nanomanufacturing processes.
In my opinion the best nanosystems are going to be done by 3-D printing because it would bypass the problems of standard microfabrication Velsquez-Garca says.
Using their nanotube forest they're able to get the devices to operate in pure ion mode
#Creating nanostructures using simple stamps Nanostructures of virtually any possible shape can now be made using a combination of techniques developed by the MESA+Institute for Nanotechnology of the University of Twente.
Research has been done within the Inorganic Materials science group part of the MESA+Institute for Nanotechnology at the University of Twente.
#Researcher develops optically traceable smart 2-D nanosheet that responds to ph Nanoparticles have the potential to revolutionize the medical industry
Finally they need to perform their function at the right moment ideally in response to a stimulus. The Nanoparticles By design Unit at the Okinawa Institute of Science
when he experimented with a new type of nanomaterial: the nanosheet. Specifically he designed a strong stable
and optically traceable smart 2-D material that responds to ph or the acidity or basicity of its surrounding environment.
Nanosheets are unusual amongst nanotechnology because they do not exactly conform to nanoscale. The sheets that Kim produced are just a few nanometers thick thin enough to earn the nano prefix.
But their length and width can be measured in microns sometimes with surface areas that can be measured in centimeters;
much larger than typical nanostructures.##Nanosheets'structure gives them the ability to change shape from a flat surface to a scroll.
Unfortunately most nanosheets roll and unroll spontaneously. If researchers can design a nanosheet to change form in response to a stimulus they can use it for a number of new applications.
Kim tried adding different polymers to his nanosheets to make them responsive. For this experiment he incorporated a relatively simple polymer that responds to ph. He found that the resulting nanosheet would always curl in basic high ph conditions
and always flatten in acidic low ph conditions. Kim also made his nanosheets responsive to near-infrared light a wavelength of light that is harmless to humans.
Depending on the shape of the nanosheet the near-infrared radiation bounces back with a different wavelength.
In this way Kim can noninvasively track the nanosheets even though he can't see them. Using these optical properties to characterize the nanosheets Kim determined that he could approximate ph. Kim envisions biomedical engineers wrapping drugs inside of scrolled nanosheets
so that when the sheet unrolls it releases the medicine. PH responsive nanosheets for example could prove useful for targeting different parts of the human digestive tract
which changes ph between the acidic stomach and basic intestines. Yet this is only the beginning;
creating a responsive nanosheet is just a matter of adding the right polymer. A nanosheet is like pizza dough Kim said.
Whatever you like to put on it#one topping two toppings anything#you can. A nanosheet with a heat-sensitive polymer could burn surrounding tumors to destroy them functioning as a kind of super-specific chemotherapy.
It's easy to get the nanosheets to the cancer cells explains Kim. Targeting specific tissues is simply a matter of adding the appropriate biomarker
so that the body sends the nanosheet where it belongs. The advantage of the rolling means that this nanosheet can entrap many markers
or drugs securely inside the body said Kim. By encapsulating a dangerous substance such as a cancer-treating drug into a nanosheet doctors can attack very specific parts of the body.
This would decrease the amount of the drug necessary and minimize side effects. There are tons of smart polymers
and metals Kim said explaining the many properties he hopes to incorporate into nanotechnology. This new structure is composite
which means it allows us to mix all different kinds of components. Now Kim just needs to build the right nanosheet for each purpose.
Explore further: Like cling wrap new biomaterial can coat tricky burn wounds and block out infection More information:
Smart Composite Nanosheets with Adaptive Optical Properties Jeong-Hwan Kim Murtaza Bohra Vidyadhar Singh Cathal Cassidy and Mukhles Sowwan Applied materials & Interfaces2014.
American Chemical Society DOI: 10.1021/am504170
#New nanomaterial introduced into electrical machines Lappeenranta University of Technology in Finland has constructed the world's first prototype electrical motor using carbon nanotube yarn in the motor windings.
The new technology may significantly enhance the performance. Engineers of LUT have constructed the world's first electrical motor applying a textile material;
carbon nanotube yarn. The presently most electrically conductive carbon nanotube yarn replaces usual copper wires in the windings.
The motor prototype is built by the LUT Electrical engineering group as a start towards lightweight efficient electric drives.
The test motor output power is 40 W it rotates at 15000 rpm and has almost a 70%efficiency.
In the near future carbon nanotube fibers have potential to significantly enhance the performance and energy efficiency of electrical machines.
The new technology may revolutionize the whole industry. Researchers are constantly searching for opportunities to upgrade the performance of electrical machines;
to this end one of the objectives is to find higher-conductivity wires for the windings.
The best carbon nanotubes (CNTS) have demonstrated conductivities far beyond those of the best metals. Thus future windings made of CNTS may have a double conductivity compared with the present-day copper windings.
In order to make CNTS easy to manipulate they are spun to form multifiber yarn. If we keep the electrical machine design parameters unchanged and only replace copper with future carbon nanotube wires it is possible to reduce the Joule losses in the windings to half of the present-day machine losses.
Carbon nanotube wires are significantly lighter than copper and also environmentally friendlier. Therefore replacing copper with nanotube wires should significantly reduce the CO2 EMISSIONS related to the manufacturing
and operating of electrical machines. Furthermore the machine dimensions and masses could be reduced. The motors could also be operated in significantly higher temperatures than the present ones says Professor Juha Pyrh nen who has led the design of the prototype at LUT.
No definite upper limit for the conductivity Traditionally the windings in electrical machines are made of copper which has the second best conductivity of metals at room temperature.
Despite the high conductivity of copper a large proportion of the electrical machine losses occur in the copper windings.
The carbon nanotube yarn does not have a definite upper limit for conductivity (e g. values of 100 MS/m have already been measured.
The prototype motor uses carbon nanotube yarns spun and converted into an isolated tape by a Japanese-Dutch company Teijin Aramid
We expect that in the future the conductivity of carbon nanotube yarns could be even three times the practical conductivity of copper in electrical machines.
Carbon nanotube fibers outperform coppe e
#New absorber will lead to better biosensors Biological sensors or biosensors are like technological canaries in the coalmine.
Currently plasmonic absorbers used in biosensors have a resonant bandwidth of 50 nanometers said Koray Aydin assistant professor of electrical engineering and computer science at Northwestern University's Mccormick School of engineering and Applied science.
Aydin and his team have created a new nanostructure that absorbs a very narrow spectrum of light#having a bandwidth of just 12 nanometers.
By using nanofabrication techniques in the lab Aydin's team found that removing the insulating layer#leaving only metallic nanostructures#caused the structure to absorb a much narrower band of light.
#'Stealth'nanoparticles could improve cancer vaccines Cancer vaccines have emerged recently as a promising approach for killing tumor cells before they spread.
And the key they report in the journal ACS Nano is in the vaccine's unique stealthy nanoparticles.
if stealthy nanoparticles they had developed and clinically tested in patients might hold the answer. The researchers injected the nanoparticles into mice.
They found that the particles which have no electric charge or surface molecules that would attract the attention of circulating immune cells were able to enter the mice's lymph nodes.
When molecules for signaling killer T cells were put inside the nanoparticles they hindered tumor growth far better than existing vaccines.
Nanogel-Based Immunologically Stealth Vaccine Targets Macrophages in the Medulla of Lymph node and Induces Potent Antitumor Immunity ACS Nano 2014 8 (9) pp 9209#9218.
We developed a nanoparticulate cancer vaccine by encapsulating a synthetic long peptide antigen within an immunologically inert nanoparticulate hydrogel (nanogel) of cholesteryl pullulan (CHP.
After subcutaneous injection to mice the nanogel-based vaccine was transported efficiently to the draining lymph node and was engulfed preferentially by medullary macrophages
The nanogel-based vaccine significantly inhibited in vivo tumor growth in the prophylactic and therapeutic settings compared to another vaccine formulation using a conventional delivery system incomplete Freund's adjuvant.
which may underlie the potency of the macrophage-oriented nanogel-based vaccine. These results indicate that targeting medullary macrophages using the immunologically stealth nanoparticulate delivery system is an effective vaccine strategy e
#Nanoparticles accumulate quickly in wetland sediment (Phys. org) A Duke university team has found that nanoparticles called single-walled carbon nanotubes accumulate quickly in the bottom sediments of an experimental wetland setting an action they say could indirectly damage the aquatic food chain.
The results indicate little risk to humans ingesting the particles through drinking water say scientists at Duke's Center for the Environmental Implications of Nanotechnology (CEINT.
But the researchers warn that based on their previous research the tendency for the nanotubes to accumulate in sediment could indirectly damage the aquatic food chain in the long term
if the nanoparticles provide Trojan horse piggyback rides to other harmful molecules. The results appear online in the journal Environmental science:
Ferguson and his colleagues dosed the mesocosms with single-walled carbon nanotubes and measured their concentrations in the water soil and living organisms during the course of a year.
They found that the vast majority of the nanoparticles quickly accumulated in the sediment on the pond floor.
However they found no sign of nanoparticle buildup in any plants insects or fish living in the mesocosms.
These nanoparticles are really good at latching onto other molecules including many known organic contaminants said Ferguson.
The nanoparticle-pollutant package could then be eaten by sediment-dwelling organisms in a sort of'Trojan horse'effect allowing the adsorbed contaminants to accumulate up the food chain.
Fate of single walled carbon nanotubes in wetland ecosystems. Schierz A. Espinasse B. Wiesner M. R. Bisesi J. H. Sabo-Attwood T. Ferguson P. L. Environmental science:
#All directions are created not equal for nanoscale heat sources Thermal considerations are rapidly becoming one of the most serious design constraints in microelectronics, especially on submicron scale lengths.
a professor of materials science and engineering at Illinois."Our current understanding of nanoscale thermal transport isn't nuanced enough to quantitatively predict
Wilson and Cahill also studied the effect of interfaces on nanoscale thermal transport.""It's been well known for 75 years that the presence of a boundary adds a thermal boundary resistance to the heat-transfer problem,
"Wilson and Cahill also provided a theoretical description of their results that can be used by device engineers to better manage heat and temperature in nanoscale devices c
Their experiments show that future computer chips could be based on three-dimensional arrangements of nanometer scale magnets instead of transistors.
They report their latest results in the journal Nanotechnology. In a 3d stack of nanomagnets, the researchers have implemented a so-called majority logic gate
which could serve as a programmable switch in a digital circuit. They explain the underlying principle with a simple illustration:
Gates made from field-coupled nanomagnets work in an analogous way, with the reversal of polarity representing a switch between Boolean logic states,
of which sits 60 nanometers below the other two, and is read out by a single output magnet.
So-called domain walls generated there are able to flow through magnetic wires under the control of surrounding nanomagnets.
The most basic building blocks, the individual nanomagnets, are comparable in size to individual transistors. Furthermore, where transistors require contacts and wiring,
nanomagnets operate purely with coupling fields. Also, in building CMOS and nanomagnetic devices that have the same function for example
TUM doctoral candidate Irina Eichwald, lead author of the Nanotechnology paper, explains:""The 3d majority gate demonstrates that magnetic computing can be exploited in all three dimensions,
Briseno with colleagues and graduate students at UMASS Amherst and others at Stanford university and Dresden University of Technology Germany report in the current issue of Nano Letters that by using single-crystalline organic nanopillars
or nanograss they found a way to get around dead ends or discontinuous pathways that pose a serious drawback when using blended systems known as bulk heterojunction donor-acceptor or positive-negative (p-n) junctions for harvesting energy in organic solar cells.
We report here that we have developed at last the ideal architecture composed of organic single-crystal vertical nanopillars.
Nanopillars are engineered nanoscale surfaces with billions of organic posts that resemble blades of grass and like grass blades they are particularly effective at converting light to energy.
In this case the anisotropy is along the nanopillar perpendicular to the substrate. Briseno says The biggest challenge in producing this architecture was finding the appropriate substrate that would enable the molecules to stack vertically.
Vertical nanopillars are ideal geometries for getting around these challenges Briseno says because charge separation/collection is most efficient perpendicular to the plastic device.
In this case our nanopillars highly resemble nanograss. Our systems share similar attributes of grass such as high density array system vertical orientations
We envision that our nanopillar solar cells will appeal to low-end energy applications such as gadgets toys sensors and short lifetime disposable devices s
and Center for Nanoscience and Nanotechnology, have been developing sophisticated micro -and nanotechnological toolsanging in size from one millionth to one billionth of a metero develop functional substitutes for damaged heart tissues.
Searching for innovative methods to restore heart function especially cardiac"patches"that could be transplanted into the body to replace damaged heart tissue,
which incorporates biomaterial harvested from patients and gold nanoparticles.""Our goal was said twofold Dr. Dvir.""To engineer tissue that would not trigger an immune response in the patient,
"At his Laboratory for Tissue Engineering and Regenerative medicine, Dr. Dvir explored the integration of gold nanoparticles into cardiac tissue to optimize electrical signaling between cells."
we deposited gold nanoparticles on the surface of our patient-harvested matrix, 'decorating'the biomaterial with conductors,
"The result was that the nonimmunogenic hybrid patch contracted nicely due to the nanoparticles, transferring electrical signals much faster and more efficiently than non-modified scaffolds."
#Nanotube cathode beats large pricey laser Scientists are a step closer to building an intense electron beam source without a laser.
Using the High-Brightness Electron Source Lab at DOE's Fermi National Accelerator Laboratory a team led by scientist Luigi Faillace of Radiabeam Technologies is testing a carbon nanotube cathode about the size of a nickel
Tests with the nanotube cathode have produced beam currents a thousand to a million times greater than the one generated with a large pricey laser system.
While carbon nanotube cathodes have been studied extensively in academia Fermilab is the first facility to test the technology within a full-scale setting.
but at the nanoscale it resembles in Piot's words millions of lightning rods. When a strong electric field is applied it pulls streams of electrons off the surface of the cathode creating the electron beam.
The tested nanotube cathode requires no laser: it only needs the electric field already generated by an accelerator to siphon the electrons off a process dubbed field emission n
#Nanoengineering enhances charge transport promises more efficient future solar cells Solar cells based on semiconducting composite plastics and carbon nanotubes is one of the most promising novel technology for producing inexpensive printed solar cells.
This is achieved thanks to clever nanoengineering of the active layer inside the device. Their results are published as front page news in the journal Nanoscale.
Carbon nanotubes are more and more attractive for use in solar cells as a replacement for silicon. They can be mixed in a semiconducting polymer
and the nanotubes have outstanding electrical conductivity, and they can effectively separate and transport electrical charges generated from solar energy.
and charge transport at very low nanotube loadings, thereby strongly reducing materials costs o
#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.
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
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
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