#Electrical cables that store energy? New nanotech may provide power storage in electric cables clothes Imagine being able to carry all the juice you needed to power your MP3 PLAYER, smartphone and electric car in the fabric of your jacket?
Sounds like science fiction, but it may become a reality thanks to breakthrough technology developed at a University of Central Florida research lab. So far electrical cables are used only to transmit electricity.
However, nanotechnology scientist and professor Jayan Thomas and his Ph d. student Zenan Yu have developed a way to both transmit and store electricity in a single lightweight copper wire.
Their work is the focus of the cover story of the June 30 issue of the material science journal Advanced Materials and science magazine,
Nature has published a detailed discussion about this technology in the current issue.""It's a very interesting idea,
special fibers could also be developed with nanostructures to conduct and store energy. More immediate applications could be seen in the design
and development of electrical vehicles, space-launch vehicles and portable electronic devices. By being able to store
and conduct energy on the same wire, heavy, space-consuming batteries could become a thing of the past.
It is possible to further miniaturize the electronic devices or the space that has been used previously for batteries could be used for other purposes.
In the case of launch vehicles that could potentially lighten the load, making launches less costly,
Thomas said. So how did he get the idea about energy-storing cables? He was inspired during a routine evening walk in his neighborhood.
These whiskers were treated then with a special alloy, which created an electrode. Two electrodes are needed for the powerful energy storage.
So they had to figure out a way to create a second electrode. They did it-this by adding a very thin plastic sheet around the whiskers
and wrapping it around using a metal sheath (the second electrode) after generating nanowhiskers on it (the second electrode and outer covering).
The layers were glued then together with a special gel. Because of the insulationthe nanowhisker layer is insulating,
the inner copper wire retains its ability to channel electricity, the layers around the wire independently store powerful energy.
In other words, Thomas and his team created a supercapacitor on the outside of the copper wire. Supercapcitors store powerful energy,
like that needed to start a vehicle or heavy-construction equipment. Although more work needs to be done,
Thomas said the technique should be transferable to other types of materials. That could lead to specially treated clothing fibers being able to hold enough power for big tasks.
For example if flexible solar cells and these fibers were used in tandem to make a jacket, it could be used independently to power electronic gadgets and other devices."
"It's very exciting, "Thomas said.""We take it step by step. I love getting to the lab everyday,
and seeing what we can come up with next. Sometimes things don't work out, but even those failures teach us a lot of things.
Still, I know how important getting out of the lab can be too. I won't be giving up those evening walks anytime soon.
I get some great ideas during that quiet time
#Nanotechnology takes on diabetes A sensor which can be used to screen for diabetes in resource-poor settings has been developed by researchers
and tested in diabetic patients, and will soon be tested field in Sub-saharan africa. A low-cost, reusable sensor which uses nanotechnology to screen for
and monitor diabetes and other conditions, has been developed by an interdisciplinary team of researchers from the University of Cambridge, for use both in clinics and home settings.
The sensors use nanotechnology to monitor levels of glucose, lactate and fructose in individuals with diabetes or urinary tract infections
and change colour when levels reach a certain concentration. They can be used to test compounds in samples such as urine, blood, saliva or tear fluid.
Earlier this year, clinical trials of the sensors were carried out at Addenbrooke's Hospital to monitor glucose levels in 33 diabetic patients.
Recently, the team has partnered also with a non-governmental organisation to deploy the technology for field use in Ghana early next year.
According to the International Diabetes Federation, there are an estimated 175 million undiagnosed diabetic patients worldwide, 80%of
whom live in low-and middle-income countries. Development of noninvasive and accurate diagnostics that are manufactured easily
robust and reusable will allow for simple monitoring of high-risk individuals in any environment, particularly in the developing world.
The sensors developed by the Cambridge team are made using laser light, which organises metal nanoparticles into alternating layers in thin gel films to produce the sensors in a matter of seconds.
When glucose, lactate or fructose concentrations are high in a sample, the sensor changes colour.
The exact concentration can be determined by visually comparing the colour to a reference chart, or the image can be processed automatically by a smartphone application.
In trials conducted earlier this year in Cambridge the sensors showed improved performance over commercial glucose test strips read by an automated reader,
while showing comparable performance state-of-the-art fully-automated glucose monitoring technology. Details were published recently in the journal Nano Letters.
Additionally, the sensors can be produced at a fraction of the cost of commercially-available test strips.
A single sensor would cost 20 pence to produce, and can be reused up to 400 times,
compared with disposable urine test strips, which cost about 10 pence per use. The use of lasers means that the sensors can be manufactured easily at scale."
"These sensors can be used to screen for diabetes in resource-poor countries, where disposable test strips and other equipment are simply not affordable,
"said Ali Yetisen, a Phd candidate in the Department of Chemical engineering & Biotechnology, who led the research.
The researchers are developing a prototype smartphone-based test suitable for both clinical and home testing of diabetes and other clinically relevant conditions."
"The value of these reusable sensors will be realised when they are mass produced and adopted as a diagnostic tool for routine diabetes screening,
"said Yunuen Montelongo who co-authored the article e
#New method stabilizes common semiconductors for solar fuels generation Researchers around the world are trying to develop solar-driven generators that can split water yielding hydrogen gas that could be used as clean fuel.
Such a device requires efficient light-absorbing materials that attract and hold sunlight to drive the chemical reactions involved in water splitting.
Semiconductors like silicon and gallium arsenide are excellent light absorberss is clear from their widespread use in solar panels.
However these materials rust when submerged in the type of water solutions found in such systems.
Now Caltech researchers at the Joint Center for Artificial Photosynthesis (JCAP) have devised a method for protecting these common semiconductors from corrosion even as the materials continue to absorb light efficiently.
The finding paves the way for the use of these materials in solar fuel generators. For the better part of a half century these materials have been considered off the table for this kind of use says Nate Lewis the George L. Argyros Professor and professor of chemistry at Caltech and the principal investigator on the paper.
But we didn't give up on developing schemes by which we could protect them and now these technologically important semiconductors are back on the table.
The research led by Shu Hu a postdoctoral scholar in chemistry at Caltech appears in the May 30 issue of the journal Science.
In the type of integrated solar fuel generator that JCAP is striving to produce two half-reactions must take placene involving the oxidation of water to produce oxygen gas;
and numerous techniques for coating the common light-absorbing semiconductors. The problem has been that if the protective layer is too thin the aqueous solution penetrates through
and corrodes the semiconductor. If on the other hand the layer is too thick it prevents corrosion but also blocks the semiconductor from absorbing light and keeps electrons from passing through to reach the catalyst that drives the reaction.
At Caltech the researchers used a process called atomic layer deposition to form a layer of titanium dioxide (Tio2) material found in white paint and many toothpastes and sunscreensn single crystals of silicon gallium arsenide
or gallium phosphide. The key was used that they a form of Tio2 known as leaky Tio2ecause it leaks electricity.
First made in the 1990s as a material that might be useful for building computer chips leaky oxides were rejected as undesirable because of their charge-leaking behavior.
However leaky Tio2 seems to be just what was needed for this solar fuel generator application Deposited as a film ranging in thickness between 4 and 143 nanometers the Tio2 remained optically transparent on the semiconductor crystalsllowing them to absorb lightnd protected them from corrosion
but allowed electrons to pass through with minimal resistance. On top of the Tio2 the researchers deposited 100-nanometer-thick islands of an abundant inexpensive nickel oxide material that successfully catalyzed the oxidation of water to form molecular oxygen.
The work appears to now make a slew of choices available as possible light-absorbing materials for the oxidation side of the water-splitting equation.
However the researchers emphasize it is known not yet whether the protective coating would work as well if applied using an inexpensive less-controlled application technique such as painting or spraying the Tio2 onto a semiconductor.
Also thus far the Caltech team has tested only the coated semiconductors for a few hundred hours of continuous illumination.
This is already a record in terms of both efficiency and stability for this field but we don't yet know
Water-splitting photocatalyst that is abundant and inexpensive with low toxicity discovered More information: Amorphous Tio2 coatings stabilize Si Gaas and Gap photoanodes for efficient water oxidationn by S. Hu et al.
#Using gold nanoprobes to unlock your genetic profile A fast and cost-effective genetic test to determine the correct dosage of blood thinning drugs for the treatment of stroke,
heart problems and deep vein thrombosis has been developed by researchers at the Institute of Bioengineering and Nanotechnology (IBN).
Using gold nanoprobes, this new technology offers personalized healthcare based on the genetic profile of the patients.
IBN Executive director Professor Jackie Y. Ying said, "Diseases caused by blood clots can be potentially fatal.
Genetic testing can improve the treatment of such medical conditions. By combining our expertise in molecular diagnostics and nanotechnology,
we have developed a new genetic test that can determine the appropriate drug dosage to be administered for each patient."
"Blood thinning drugs or anticoagulant medication prevent clots from forming in the blood. They are used to treat stroke, irregular heartbeat and deep vein thrombosis.
Warfarin is the most widely prescribed oral anticoagulant drug. But the dosage for each individual is highly variable,
Doctors currently determine the right dosage by monitoring the patients'reactions and adjusting the dosage accordingly.
therefore help doctors to decide the correct dosage for the patient. This minimizes side effects and improves treatment outcomes.
By using gold nanoprobes, IBN's test kit can recognize three of the most common genetic variations,
or single-nucleotide polymorphisms, associated with warfarin response. In the test, DNA is extracted from blood or saliva of patients.
it is added then to a pink solution of gold nanoparticles. If any of the three genetic variations is present
the solution will remain pink. But if none of the variations is present, the solution will turn colorless.
IBN's test has been validated by the National Cancer Centre Singapore, the National University Cancer Institute Singapore,
Prof Ying added,"This nanoprobe technology is highly flexible and can be extended to detect other genetic variations.
By making molecular diagnostics information more readily available, doctors will be able to provide personalized treatment that is safer and more effective
#New breed of solar cells: Quantum dot photovoltaics set new record for efficiency in such devices Solar-cell technology has advanced rapidly as hundreds of groups around the world pursue more than two dozen approaches using different materials technologies
and approaches to improve efficiency and reduce costs. Now a team at MIT has set a new record for the most efficient quantum dot cells a type of solar cell that is seen as especially promising because of its inherently low cost versatility and light weight.
While the overall efficiency of this cell is still low compared to other types about 9 percent of the energy of sunlight is converted to electricity the rate of improvement of this technology is one of the most rapid seen for a solar technology.
The development is described in a paper published in the journal Nature Materials by MIT professors Moungi Bawendi and Vladimir Buloviä#and graduate students Chia-Hao Chuang and Patrick Brown.
The new process is an extension of work by Bawendi the Lester Wolfe Professor of Chemistry to produce quantum dots with precisely controllable characteristics
and as uniform thin coatings that can be applied to other materials. These minuscule particles are very effective at turning light into electricity and vice versa.
Since the first progress toward the use of quantum dots to make solar cells Bawendi says The community in the last few years has started to understand better how these cells operate and
what the limitations are. The new work represents a significant leap in overcoming those limitations increasing the current flow in the cells
and thus boosting their overall efficiency in converting sunlight into electricity. Many approaches to creating low-cost large-area flexible and lightweight solar cells suffer from serious limitations such as short operating lifetimes
when exposed to air or the need for high temperatures and vacuum chambers during production. By contrast the new process does not require an inert atmosphere
or high temperatures to grow the active device layers and the resulting cells show no degradation after more than five months of storage in air.
Buloviä#the Fariborz Maseeh Professor of Emerging Technology and associate dean for innovation in MIT's School of engineering explains that thin coatings of quantum dots allow them to do what they do as individuals to absorb light very well
but also work as a group to transport charges. This allows those charges to be collected at the edge of the film where they can be harnessed to provide an electric current.
The new work brings together developments from several fields to push the technology to unprecedented efficiency for a quantum dot based system:
The paper's four co-authors come from MIT's departments of physics chemistry materials science and engineering and electrical engineering and computer science.
The solar cell produced by the team has now been added to the National Renewable energy Laboratories'listing of record-high efficiencies for each kind of solar-cell technology.
The overall efficiency of the cell is still lower than for most other types of solar cells.
But Buloviä#points out Silicon had six decades to get where it is today and even silicon hasn't reached the theoretical limit yet.
And the new technology has important advantages notably a manufacturing process that is far less energy-intensive than other types.
Chuang adds Every part of the cell except the electrodes for now can be deposited at room temperature in air out of solution.
along with MIT's Jeffrey Grossman the Carl Richard Soderberg Associate professor of Power engineering and three others appears this month in the journal ACS Nano explaining in greater detail the science behind the strategy employed to reach this efficiency breakthrough.
The new work represents a turnaround for Bawendi who had spent much of his career working with quantum dots.
But his team's research since then has demonstrated clearly quantum dots'potential in solar cells he adds.
Arthur Nozik a research professor in chemistry at the University of Colorado who was involved not in this research says This result represents a significant advance for the applications of quantum dot films and the technology of low-temperature solution-processed quantum dot photovoltaic cells.#
#There is still a long way to go before quantum dot solar cells are commercially viable but this latest development is a nice step toward this ultimate goal.
Improved performance and stability in quantumâ dot solar cells through band alignmentâ engineering. Chia-Hao M. Chuang et al.
Received 06 december 2013 Accepted 15 april 2014 Published online 25 may 2014energy Level Modification in Lead Sulfide Quantum dot Thin Films Through Ligand Exchange.
#Flexible transparent thin film transistors raise hopes for flexible screens (Phys. org) he electronics world has been dreaming for half a century of the day you can roll a TV up in a tube.
Last year, Samsung even unveiled a smartphone with a curved screenut it was solid, not flexible;
see-through 2-D thin film transistors. These transistors are just 10 atomic layers thickhat's about how much your fingernails grow per second.
Transistors are the basis of nearly all electronics. Their two settingsn or offictate the 1s and 0s of computer binary language.
Thin film transistors are a particular subset of these that are used typically in screens and displays.
Virtually all flat-screen TVS and smartphones are made up of thin film transistors today; they form the basis of both LEDS and LCDS (liquid crystal displays."
"This could make a transparent, nearly invisible screen,"said Andreas Roelofs, a coauthor on the paper and interim director of Argonne's Center for Nanoscale Materials."
"Imagine a normal window that doubles as a screen whenever you turn it on, for example."
"To measure how good a transistor is, you measure its on-off ratioow completely can it turn off the current?
nd a property called"field effect carrier mobility, "which measures how quickly electrons can move through the material."
"We were pleased to find that the on/off ratio is just as good as current commercial thin-film transistors,"said Argonne postdoctoral scientist and first author Saptarshi Das,
"but the mobility is a hundred times better than what's on the market today.""The team also tried bending the films to test
what happens under stress. In most thin film transistors, the material starts to crack, which,
as you might imagine, affects performance.""But in ours, the properties didn't change at all,
"Roelofs said.""The layers just slide and don't crack.""The transistors also maintained performance over a wide range of temperatures (from-320°F to 250°F), a useful property in electronics,
which can run very hot. To build the transistors, the team started with a trick that earned its original University of Manchester inventors the Nobel prize:
using a strip of scotch tape to peel off a sheet of tungsten diselenide just atoms thick."
"We chose tungsten diselenide because it provides the electron and hole conduction necessary for making transistors with logic gates and other p-n junction devices,"said Argonne scientist and coauthor Anirudha Sumant.
Then they used chemical deposition to grow sheets of other materials on top to build the transistor layer by layer.
The final product is 10 atomic layers thick. See sidebar for an illustration. Next, the team is interested in adding logic and memory to flexible films,
so you could make not just a screen but an entire flexible and transparent TV or computer."
"However, more work needs to be done in developing large-area synthesis of tungsten selenide to realize the true potential for applications of our work,
#Atomic force microscope systems take a tip from nanowires (Phys. org) In response to requests from the semiconductor industry a team of PML researchers has demonstrated that atomic force microscope (AFM) probe
tips made from its near-perfect gallium nitride nanowires are superior in many respects to standard silicon
or platinum tips in measurements of critical importance to microchip fabrication nanobiotechnology and other endeavors.
In addition the scientists have invented a means of simultaneously using the nanowire tips as LEDS to illuminate a tiny sample region with optical radiation
while it is scanning adding an entirely new dimension to the characterization of nanoelectronics materials and devices.
By itself an AFM provides topographical information at nanometer resolution as its probe tip in the range of 100 nm wide
and receive a microwave signal the system becomes capable of revealing charge-carrier concentrations or defect locations in specific regions of nanoscale materials and devices.
That technique called near-field scanning microwave microscopy (NSMM) had never before been attempted using a nanowire probe.
But as the team showed in a recent paper in Applied Physics Letters nanowire probe tips substantially outperformed commercial Pt tips in both resolution and durability.
and Synthesis of 3d Nanostructures in the Quantum Electronics and Photonics Division is that if you deform them even a little bit
By contrast our nanowire probe tips have a calibration lifetime about 10 times longer than any commercial tip.
The nanowire however retained its original dimensions. Moreover the Gan tips exhibited improved sensitivity and reduced uncertainty compared to a commercial Pt tip.
and negative charge carriers inside a nanostructure#information of great practical significance to microdevice fabricators#and scientists from PML's Electromagnetics Division have made notable progress in the technique.
They believe that the use of nanowire probes in conjunction with the recent arrival of a brand-new custom-built four-probe NSMM instrument will reveal new aspects of nanostructure composition and performance.
In biological materials it could locate the attachment of chemical agents or particles that are bound to a cell and aid in the study of protein dynamics.
Deploying a nanowire as a probe tip sounds deceptively simple. The researchers obtain a conventional AFM cantilever
Then using a minuscule manipulator they break off a single nanowire from a forest of them grown by molecular beam epitaxy insert the wire into the hole and weld it in place.
and aluminum (200 nm) in order to conduct the microwave signal all the way to the end of the tip and back.
The researchers tested their tip against a silicon tip a platinum tip and an uncoated Gan nanowire each
The coated nanowire proved about twice as sensitive as the Pt probe and four times as sensitive as the others with superior mechanical performance.
and optoelectronic devices Bertness says. At present only a few Gan probes can be made at once but the team is at work on developing ideas for producing them in wafer-scale quantities.
Using the nanowire tip as a light source by doping it so that it functions as an LED.
Optical radiation can serve to excite the sample in a different way from the microwave signal
and scientists are already using lasers to illuminate nanoscale samples during AFM scans. The problem with that approach says veteran NSMM researcher Pavel Kabos of the Advanced High-frequency Devices Program in PML's Electromagnetics Division is that the laser has to shine in from the side.
As a result you get cast shadows and significant uncertainty as to exactly what area is being illuminated.
And of course the laser and its mounting take up a great deal of space. With the new design the illumination will be applied directly over the probe tip at the same place on the sample that is being exposed to the microwave signal.
That could be particularly beneficial in characterizing photovoltaic materials where you could apply a light
and the nanoscale light source enables you to inject some carriers very locally in a way you can't do with other methods.
In biological applications we expect it to provide an order of magnitude improvement in the ability to investigate processes such as protein dynamics.
Reaching that goal will require more research into how to dope the Gan nanowires so as to increase efficiency of light output
and integrate measurements from topographic microwave and optical modalities. But Bertness is optimistic. It took ten years of hard work learning how to fabricate
and characterize these materials and we developed a lot of important metrology techniques along the way. But we really weren't able to test nanowires as probe tips until a few months ago
when the Boulder lab's Precision Imaging Facility gained a focused ion beam. These initial results give us confidence that this technology will impact a broad range of science
and nanometer scale is crucial from semiconductor electronics to biochemistry and medicine. Explore further: High-resolution microscopy technique resolves individual carbon nanotubes under ambient condition c
#DNA NANOTECHNOLOGY places enzyme catalysis within an arm's length Using molecules of DNA like an architectural scaffold, Arizona State university scientists,
in collaboration with colleagues at the University of Michigan, have developed a 3-D artificial enzyme cascade that mimics an important biochemical pathway that could prove important for future biomedical and energy applications.
The findings were published in the journal Nature Nanotechnology. Led by ASU Professor Hao Yan, the research team included ASU Biodesign Institute researchers Jinglin Fu, Yuhe Yang, Minghui Liu, Professor Yan Liu
and Professor Neal Woodbury along with colleagues Professor Nils Walter and postdoctoral fellow Alexander Johnson-Buck at the University of Michigan.
Researchers in the field of DNA NANOTECHNOLOGY taking advantage of the binding properties of the chemical building blocks of DNA, twist and self-assemble DNA into evermore imaginative 2-and 3-dimensional structures for medical, electronic and energy applications.
In the latest breakthrough, the research team took up the challenge of mimicking enzymes outside the friendly confines of the cell.
These enzymes speed up chemical reactions, used in our bodies for the digestion of food into sugars and energy during human metabolism, for example."
"We look to Nature for inspiration to build man-made molecular systems that mimic the sophisticated nanoscale machineries developed in living biological systems,
and we rationally design molecular nanoscaffolds to achieve biomimicry at the molecular level, "Yan said,
who holds the Milton Glick Chair in the ASU Department of chemistry and Biochemistry and directs the Center for Molecular Design and Biomimicry at the Biodesign Institute.
With enzymes, all moving parts must be controlled tightly and coordinated, otherwise the reaction will not work.
The moving parts, which include molecules such as substrates and cofactors, all fit into a complex enzyme pocket just like a baseball into a glove.
Once all the chemical parts have found their place in the pocket the energetics that control the reaction become favorable,
to another enzyme to carry out the next step in a biochemical pathway in the human body. For the new study, the researchers chose a pair of universal enzymes, glucose 6-phosphate phosphate dehydrogenase (G6pdh) and malate dehydrogenase (MDH),
For example, defects found in the pathway cause anemia in humans.""Dehydrogenase enzymes are particularly important
since they supply most of the energy of a cell, "said Walter."Work with these enzymes could lead to future applications in green energy production such as fuel cells using biomaterials for fuel."
"In the pathway, G6pdh uses the glucose sugar substrate and a cofactor called NAD to strip hydrogen atoms from glucose and transfer to the next enzyme, MDH,
which is used for as a key cofactor for biosynthesis. Remaking this enzyme pair in the test tube
and having it work outside the cell is a big challenge for DNA NANOTECHNOLOGY. To meet the challenge,
Using a computer program, they were able to customize the chemical building blocks of the DNA sequence
so that the scaffold would self-assemble. Next the two enzymes were attached to the ends of the DNA tubes.
which can see down to the nanoscale, 1, 000 times smaller than the width of a human hair.
a red light means the reaction works. Next, they tried the enzyme system and found that it worked just the same as a cellular enzyme cascade.
"said Walter. The work also opens a bright future where biochemical pathways can be replicated outside the cell to develop biomedical applications such as detection methods for diagnostic platforms."
"An even loftier and more valuable goal is to engineer highly programmed cascading enzyme pathways on DNA NANOSTRUCTURE platforms with control of input and output sequences.
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