University of Manchester researchers have found. Published in the journal Nature the discovery could revolutionize fuel cells
and other hydrogen-based technologies as they require a barrier that only allow protons-hydrogen atoms stripped off their electrons-to pass through.
creating the possibility of electric generators powered by air. One-atom thick material graphene first isolated and explored in 2004 by a team at The University of Manchester is renowned for its barrier properties
which has a number of uses in applications such as corrosion-proof coatings and impermeable packaging.
Despite the pessimistic prognosis the researchers found that protons pass through the ultra-thin crystals surprisingly easily especially at elevated temperatures
and if the films were covered with catalytic nanoparticles such as platinum. The discovery makes monolayers of graphene
and its sister material boron nitride attractive for possible uses as proton-conducting membranes which are at the heart of modern fuel cell technology.
Fuel cells use oxygen and hydrogen as a fuel and convert the input chemical energy directly into electricity.
Without membranes that allow an exclusive flow of protons but prevent other species to pass through this technology would not exist.
Despite being established well, fuel-cell technology requires further improvements to make it more widely used. One of the major problems is a fuel crossover through the existing proton membranes
The University of Manchester research suggests that the use of graphene or monolayer boron nitride can allow the existing membranes to become thinner and more efficient with less fuel crossover and poisoning.
This can boost competitiveness of fuel cells. The Manchester group also demonstrated that their one-atom-thick membranes can be used to extract hydrogen from a humid atmosphere.
They hypothesise that such harvesting can be combined together with fuel cells to create a mobile electric generator that is fuelled simply by hydrogen present in air.
Marcelo Lozada-Hidalgo, a Phd student and corresponding author of this paper, said: When you know how it should work it is a very simple setup.
You put a hydrogen-containing gas on one side apply small electric current and collect pure hydrogen on the other side.
This hydrogen can then be burned in a fuel cell. We worked with small membranes and the achieved flow of hydrogen is of course tiny so far.
But this is the initial stage of discovery and the paper is to make experts aware of the existing prospects.
To build up and test hydrogen harvesters will require much further effort. Dr Sheng Hu a postdoctoral researcher and the first author in this work, added:
It looks extremely simple and equally promising. Because graphene can be produced these days in square metre sheets we hope that it will find its way to commercial fuel cells sooner rather than later r
#Researchers develop efficient method to produce nanoporous metals Nanoporous metals foam-like materials that have some degree of air vacuum in their structure have a wide range of applications because of their superior qualities.
They posses a high surface area for better electron transfer which can lead to the improved performance of an electrode in an electric double capacitor or battery.
Nanoporous metals offer an increased number of available sites for the adsorption of analytes a highly desirable feature for sensors.
Lawrence Livermore National Laboratory (LLNL) and The swiss Federal Institute of technology (ETH) researchers have developed a cost-effective and more efficient way to manufacture nanoporous metals over many scales from nanoscale to macroscale
which is visible to the naked eye. The process begins with a four-inch silicon wafer.
A coating of metal is added and sputtered across the wafer. Gold silver and aluminum were used for this research project.
However the manufacturing process is limited not to these metals. Next a mixture of two polymers are added to the metal substrate to create patterns a process known as diblock copolymer lithography (BCP.
The pattern is transformed in a single polymer mask with nanometer-size features. Last a technique known as anisotropic ion beam milling (IBM) is used to etch through the mask to make an array of holes creating the nanoporous metal.
During the fabrication process the roughness of the metal is examined continuously to ensure that the finished product has good porosity
which is key to creating the unique properties that make nanoporous materials work. The rougher the metal is the less evenly porous it becomes.
During fabrication our team achieved 92 percent pore coverage with 99 percent uniformity over a 4-in silicon wafer which means the metal was smooth
and evenly porous said Tiziana Bond an LLNL engineer who is a member of the joint research team.
The team has defined a metric-based on a parametrized correlation between BCP pore coverage and metal surface roughness-by which the fabrication of nanoporous metals should be stopped
when uneven porosity is known the outcome saving processing time and costs. The real breakthrough is created that we a new technique to manufacture nanoporous metals that is cheap
and can be done over many scales avoiding the lift off technique to remove metals with real-time quality control Bond said.
These metals open the application space to areas such as energy harvesting sensing and electrochemical studies. The lift off technique is a method of patterning target materials on the surface of a substrate by using a sacrificial material.
One of the biggest problems with this technique is that the metal layer cannot be peeled off uniformly (or at all) at the nanoscale.
The research team's findings were reported in an article titled Manufacturing over many scales: High fidelity macroscale coverage of nanoporous metal arrays via lift off-free nanofrabication.
It was the cover story in a recent issue of Advanced Materials Interfaces. Other applications of nanoporous metals include supporting the development of new metamaterials (engineered materials) for radiation-enhanced filtering
and manipulation including deep ultraviolet light. These applications are possible because nanoporous materials facilitate anomalous enhancement of transmitted
(or reflected light through the tunneling of surface plasmons a feature widely usable by light-emitting devices plasmonic lithography refractive-index-based sensing and all-optical switching.
Explore further: High quality three-dimensional nanoporous graphene More information: Advanced Materials Interfaces onlinelibrary. wiley. com/store/#et/admi201400084. pd
#Breakthrough in flexible electronics enabled by inorganic-based laser lift off Flexible electronics have been touted as the next generation in electronics in various areas ranging from consumer electronics to bio-integrated medical devices.
In spite of their merits insufficient performance of organic materials arising from inherent material properties and processing limitations in scalability have posed big challenges to developing all-in-one flexible electronics systems in
which display processor memory and energy devices are integrated. The high temperature processes essential for high performance electronic devices have restricted severely the development of flexible electronics because of the fundamental thermal instabilities of polymer materials.
A research team headed by Professor Keon Jae Lee of the Department of Materials science and engineering at KAIST provides an easier methodology to realize high performance flexible electronics by using the Inorganic-based Laser Lift off (ILLO.
The ILLO process involves depositing a laser-reactive exfoliation layer on rigid substrates and then fabricating ultrathin inorganic electronic devices e g. high density crossbar memristive memory on top of the exfoliation layer.
By laser irradiation through the back of the substrate only the ultrathin inorganic device layers are exfoliated from the substrate
as a result of the reaction between laser and exfoliation layer and then subsequently transferred onto any kind of receiver substrate such as plastic paper and even fabric.
This ILLO process can enable not only nanoscale processes for high density flexible devices but also the high temperature process that was previously difficult to achieve on plastic substrates.
The transferred device successfully demonstrates fully-functional random access memory operation on flexible substrates even under severe bending.
Professor Lee said By selecting an optimized set of inorganic exfoliation layer and substrate a nanoscale process at a high temperature of over 1000c can be utilized for high performance flexible electronics.
The ILLO process can be applied to diverse flexible electronics such as driving circuits for displays and inorganic-based energy devices such as battery solar cell and self-powered devices that require high temperature processes s
#Research reveals how our bodies keep unwelcome visitors out of cell nuclei The structure of pores found in cell nuclei has been uncovered by a UCL-led team of scientists,
revealing how they selectively block certain molecules from entering, protecting genetic material and normal cell functions.
The discovery could lead to the development of new drugs against viruses that target the cell nucleus
and new ways of delivering gene therapies, say the scientists behind the study. At the heart of every cell in our body is a cell nucleus,
a dense structure that contains our DNA. For a cell to function normally it needs to surround its nucleus with a protective membrane
so the membrane is pierced by hundreds of tiny gateways known as nuclear pores. The research, published today in Nature Nanotechnology,
reports on nuclear pores in frog eggs and reveals how these pores can act like a supercharged sieve,
from the London Centre for Nanotechnology (UCL Mathematics & Physical sciences), said:""The pores have been known to act like a sieve that could hold back sugar
"Dr Ariberto Fassati, co-lead author from the Wohl Virion Centre (UCL Infection & Immunity), added:"
because the pores are too small for optical microscopy and too flexible and mobile for X-ray crystallography."
the research may also hold promise for the development of new antiviral drugs and better delivery mechanisms for gene therapy.
It may also be possible to improve on the design of current mechanisms for delivering gene therapy to better cross the nuclear pores
and deliver their therapeutic genes into the nucleus
#Researchers move ultrafast low-cost DNA sequencing technology a step closer to reality A team of scientists from Arizona State university's Biodesign Institute
and IBM's T. J. Watson Research center have developed a prototype DNA reader that could make whole genome profiling an everyday practice in medicine.
and protein diagnostic devices into every single doctor's office said Stuart Lindsay an ASU physics professor and director of Biodesign's Center for Single Molecule Biophysics.
Such technology could help usher in the age of personalized medicine where information from an individual's complete DNA
Such game-changing technology is needed to make genome sequencing a reality. The current hurdle is to do so for less than $1000 an amount for
which insurance companies are more likely to provide reimbursement. In their latest research breakthrough the team fashioned a tiny DNA reading device a thousands of times smaller than width of a single human hair.
Making the solid-state device is just like making a sandwich just with ultra high-tech semiconductor tools used to slice
First they made a sandwich composed of two metal electrodes separated by a two-nanometer thick insulating layer (a single nanometer is 10000 times smaller than a human hair) made by using a semiconductor technology called atomic layer deposition.
The technology we've developed might just be the first big step in building a single-molecule sequencing device based on ordinary computer chip technology said Lindsay.
Previous attempts to make tunnel junctions for reading DNA had one electrode facing another across a small gap between the electrodes
This made it impossible to use computer chip manufacturing methods to make devices said Lindsay.
Our approach of defining the gap using a thin layer of dielectric (insulating material between the electrodes
What is more the recognition tunneling technology we have developed allows us to make a relatively large gap (of two nanometers) compared to the much smaller gaps required previously for tunnel current read-out (which were less than a single nanometer wide.
and gives DNA molecules room to pass the electrodes. 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.
A few more modifications are made to polish and finish the device manufacturing. The team encountered considerable device-to-device variation
while flowing through the two-nanometer gap. The research team is also working on modifying the technique to read other single molecules which could be used in an important technology for drug development.
to Agilent technologies in 2005. The research was funded by the National institutes of health's National Human genome Research Institute Roche and published in the journal ACS Nano.
Explore further: New material could enhance fast and accurate DNA sequencin n
#Nanoparticles infiltrate kill cancer cells from within Conventional treatment seeks to eradicate cancer cells by drugs and therapy delivered from outside the cell
which may also affect (and potentially harm) nearby normal cells. In contrast to conventional cancer therapy a University of Cincinnati team has developed several novel designs for iron-oxide based nanoparticles that detect diagnose
and destroy cancer cells using photo-thermal therapy (PTT). PTT uses the nanoparticles to focus light-induced heat energy only within the tumor harming no adjacent normal cells.
The results of the UC work will be presented at the Materials Research Society Conference in Boston Nov 30-Dec 5 by Andrew Dunn doctoral student in materials science engineering in UC's College of Engineering and Applied science.
Working with Dunn in this study are Donglu Shi professor of materials science engineering in UC's College of Engineering and Applied science;
David Mast associate professor of physics in UC's Mcmicken College of Arts and Sciences; and Giovanni Pauletti associate professor in the James L. Winkle College of Pharmacy.
The UC study used the living cells of mice to successfully test the efficacy of their two-sided nanoparticle designs (one side for cell targeting and the other for treatment delivery) in combination with the PTT.
However the U s. Food and Drug Administration has approved now the use of iron-oxide nanoparticles in humans.
That means the photo-thermal effect of iron-oxide nanoparticles may show in the next decade a strong promise in human cancer therapy likely with localized tumors.
With this technology a low-power laser beam is directed at the tumor where a small amount of magnetic iron-oxide nanoparticles are present either by injecting the particles directly into the tumor
or injecting them into the blood stream whereby the particles find and bind to the abnormal cancer cells via cell-specific targeting.
Sufficient heat is generated then locally by the laser light raising the tumor temperature rapidly to above 43 degrees Celsius
and thereby burning the abnormal cancer cells. This particular PTT treatment does not involve any medicine
but only generates local heat within the tumor therefore posing much less side effects than the traditional chemo or radiation therapies.
This treatment is much more ideal because it goes straight to the cancer cell says Shi.
The nanomaterials enter only the abnormal cells illuminating those cells and then doing whatever it is you have designed them to do.
In this case it is to heat up hot enough to burn and kill the cancer cells but not harm the surrounding normal cells.
Shi added that physicians are frustrated often with the current conventional means for early imaging of cancer cells through Medical Resonance Imaging
or Computerized Tomography scans because the tumors are usually stage three or four before they can be detected.
He stated With nanomaterial technology we can detect the tumor early and kill it on sight at the same time.
Each tumor has a corresponding protein that is cancer specific called a tumor specific ligand or an antibody antigen reaction that only has expression for that specific cancer such as breast or prostate cancer.
Scientists identify this certain biomarker that is specific to a certain tumor then conjugates this biomarker on the surface of the nanocarrier that only has the expression for that specific kind of cancer cell.
It then only targets the abnormal cancer cell not normal healthy cells and because it is so small it can break the membrane
and enter that conjugated cancer cell and release the PTT. The nanotech carriers go into the body through a vein in the blood stream seek the abnormal cancer cells find the biomarker
or cancer cells and attach to those cells and unlock their florescent particles so they can be detected by a photon laser light.
The laser light heats the nanoparticles to at least 43 degrees Celsius to kill the cancer cells ultimately leaving all the other cells in the body unharmed.
The procedure can ultimately be carried out by the patient following training to direct a small laser light device to the affected area for a specified amount of time two to three times a day.
Future research in nanoparticle PTT will look at toxicity biodegradability and compatibility issues. Shi said that the team is currently looking for other diverse biodegradable materials to use for the carriers such as plant chlorophylls like those in cabbage that are both edible and photothermal.
This material is biocompatible and biodegradable and can potentially stay in the tumor cells until its job is finished then dissolve
and be passed out through the digestive system m
#Researchers create 3-D stereoscopic color prints with nanopixels (Phys. org) By designing nanopixels that encode two sets of information
or colors of light within the same pixel researchers have developed a new method for making 3d color prints.
Each pixel can exhibit one of two colors depending on the polarization of the light used to illuminate it.
So by viewing the pixels under light of both polarizations two separate images can be seen.
The researchers led by Professor Joel K. W. Yang at A*STAR (the Agency for Science Technology
and Research) in Singapore the National University of Singapore and the Singapore University of Technology and Design have published a paper on the new technique for realizing 3d full-color stereoscopic prints in a recent issue of Nature Communications.
We have created possibly the smallest-ever stereoscopic images using pixels formed from plasmonic nanostructures Yang told Phys. org.
The work is based on the concept of surface plasmon resonance: 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.
By tailoring the exact dimensions of the biaxial nanopixels researchers can generate different colors under different polarizations.
To do this the researchers created nanopixels out of tiny pieces of aluminum a hundred or so nanometers across.
For example a 130-nm x 190-nm elliptical pixel appears green under y-polarized light
Comparing the two pixel shapes the researchers found that the elliptical pixels have a broader range of polarization-dependent colors
while the nanosquare dimer pixels have lower levels of cross-talk minimizing unwanted mixing of colors.
The researchers also note that it's possible to make pixels that can encode not just two but three or more images in a single pixel.
For example nanostructures that have circularly asymmetric shapes could have more than two polarization-dependent resonances due to the additional circularly polarized dimension.
#Next generation biomarker detects tumour cells and delivers anticancer drugs Nanyang Technological University (NTU) has invented a unique biomarker with two exceptional functions.
First it lights up when it detects tumour cells to allow scientists to take a better look.
This new biomarker which has immense potential for drug development is made from a nanophosphor particle ten thousand times smaller than a grain of sand.
NTU associate professors Zhang Qichun and Joachim Loo have found a way to make the nanoparticle light up
which is the destruction of the fluorescence dye that reduces the amount of time doctors and scientists have to image a tissue sample.
Our new biomarker has eliminated effectively such key limitations which exist in existing biological markers. The breakthrough has resulted in two papers published in Small one of the world's top scientific journals for material science and nanotechnology.
Prof Loo said their new biomarker can#also release anticancer drugs by creating a layer of coating loaded with drugs on the outside of the nanoparticle.#
#The drugs are released when the biomarker lights up in response to the near-infrared light. This is the first time we are able to do bio-imaging
and potentially target the delivery of drugs at the same time as proven in small animal tests said Prof Loo a nanotechnology and bioimaging expert.
Our breakthrough will open up new doors in the various fields of nanomedicine bioimaging and cancer therapeutics.
The new biomarker also has other advantages. It has twice the contrast of conventional dyes
and is able to emit up to three different colours of light. This means that it allows for better differentiation between healthy cells and tumour cells.
Unlike other new biomarkers used for imaging such as quantum dots the NTU biomarker has also been shown to be nontoxic staying in the body for up to two days before it is passed out harmlessly.
Moving forward the team from NTU's School of Materials science and engineering will be looking to load multiple layers of drugs into their biomarker.
If successful doctors will be able to release sequentially two or more drugs through the biomarker.#
#This will benefit cancer patients as there will be fewer side effects due to the small doses administered and also higher efficacy as the biomarker has the ability to accurately target tumour cells.
The project which took three years is funded jointly by NTU the Ministry of Education and the National Research Foundation Singapore.
The discovery is an important contribution to the University's research effort in Future Healthcare
which is one of NTU's Five Peaks of Excellence#interdisciplinary research areas in which the university aims to make a global mark in.
The other four peaks include Sustainable Earth New Media the East-West knowledge hub and Innovation Asia.
Explore further: Engineers develop innovative process to print flexible electronic circuits More information: Inorganic#Organic Hybrid Nanoprobe for NIR-Excited Imaging of Hydrogen sulfide in Cell Cultures and Inflammation in a Mouse Model.
DOI: 10.1002/smll. 20140186 l
#A gut reaction Queen's university biologist Virginia Walker and Queen's SARC Awarded Postdoctoral Fellow Pranab Das have shown nanosilver
which is added often to water purification units can upset your gut. The discovery is important as people are being exposed to nanoparticles every day.
Nanosilver is used also in biomedical applications toys sunscreen cosmetics clothing and other items. We were surprised to see significant upset of the human gut community at the lowest concentration of nanosilver in this study says Dr. Das.
To our knowledge this is the first time anyone has looked at this. It is important as we are exposed more and more to nanoparticles in our everyday lives through different routes such as inhalation direct contact or ingestion.
To conduct the research Drs. Walker and Das utilized another Queen's discovery repoopulate created by Elaine Petrof (Medicine.
repoopulate is a synthetic stool substitute which Dr. Petrof designed to treat C. difficile infections.
In this instance rather than being used as therapy the synthetic stool was used to examine the impact of nanoparticles on the human gut.
The research showed that the addition of nanosilver reduced metabolic activity in the synthetic stool sample perturbed fatty acids
and significantly changed the population of bacteria. This information can help lead to an understanding of how nanoparticles could impact our gut ecosystem.
There is no doubt that the nanosilver shifted the bacterial community but the impact of nanosilver ingestion on our long-term health is currently unknown Dr. Walker says.
This is another area of research we need to explore. The findings by Drs. Das and Walker Julie AK Mcdonald (Kingston General Hospital) Dr. Petrof (KGH) and Emma Allen-Vercoe (University of Guelph) were published in the Journal of Nanomedicine and Nanotechnology.
Explore further: Building materials may impact Arctic tundra More information: omicsonline. org/open-access/na#157-7439.1000235. pd
#Paper electronics could make health care more accessible Flexible electronic sensors based on paper an inexpensive material have the potential to some day cut the price of a wide range of medical tools from helpful robots
to diagnostic tests. Scientists have developed now a fast low-cost way of making these sensors by directly printing conductive ink on paper.
They published their advance in the journal ACS Applied materials & Interfaces. Anming Hu and colleagues point out that
because paper is available worldwide at low cost it makes an excellent surface for lightweight foldable electronics that could be made
and used nearly anywhere. Scientists have fabricated already paper-based point-of-care diagnostic tests and portable DNA detectors.
But these require complicated and expensive manufacturing techniques. 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.
The researchers developed a system for printing a pattern of silver ink on paper within a few minutes
and then hardening it with the light of a camera flash. The resulting device responded to touch even
when curved folded and unfolded 15 times and rolled and unrolled 5000 times. The team concluded their durable lightweight sensor could serve as the basis for many useful applications.
Explore further: Metal ink could ease the way toward flexible electronic books displays More information:
Direct Writing on Paper of Foldable Capacitive Touch Pads with Silver nanowire Inks ACS Appl. Mater.
Interfaces Article ASAP. DOI: 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.
Rolling and folding trials which yielded only modest changes in capacitance and no loss of function coupled with touch pad functionality on curved surfaces suggest sufficient flexibility
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