and industries, including laser, solar cells, production of transistors and nanomedicine. The colloid form of these particles have very interesting properties and characteristics,
The large difference between surface and volume energy of nanoparticles is the cause of this problem.
and a member of the Kavli Energy Nanoscience Institute at Berkeley (Kavli ENSI.""The asymmetry necessary for diode behavior originates with the different exposed electrode areas and the ionic solution,
"The efficiency of the tunneling process depends intimately on the degree of alignment of the molecule's discrete energy levels with the electrode's continuous spectrum.
At the Molecular Foundry we developed an approach to accurately compute energy-level alignment and tunneling probability in single-molecule junctions.
in nearly perfect alignment with the Fermi electron energy levels of the gold electrodes. Symmetry was broken by a substantial difference in the size of the area on each gold electrode that was exposed to the ionic solution.
and the junction energy level alignment, a positive voltage increases current substantially; a negative voltage suppresses it equally significantly."
"In addition to breaking symmetry, double layers formed by ionic solution also generate dipole differences at the two electrodes,
and energy flow at the nanoscale. What is exciting to me about this field is its multidisciplinary nature-the need for both physics and chemistry-and the strong beneficial coupling between experiment and theory."
Capacitors often complement batteries in these applications because they can provide large amounts of current quickly.
"But to the best of our knowledge, this is the first time these two types of materials have been combined into high-density energy storage devices."
"The research, supported by the Office of Naval Research and the Air force Office of Scientific research, was reported July 14 in the journal Advanced Energy Materials.
The need for efficient, high-performance materials for electrical energy storage has been growing along with the ever-increasing demand for electrical energy in mobile applications.
But it has been challenging to find a single dielectric material able to maximize permittivity, breakdown strength, energy density and energy extraction efficiency.
"It's really a bilayer hybrid material that takes the best of both reorientation polarization and approaches for reducing injection and improving energy extraction."
"In their structures, the researchers demonstrated maximum extractable energy densities up to 40 joules per cubic centimeter, an energy extraction efficiency of 72 percent at a field strength of 830 volts per micron,
The performance exceeds that of conventional electrolytic capacitors and thin-film lithium ion batteries, though it doesn't match the lithium ion battery formats commonly used in electronic devices and vehicles."
"This is the first time I've seen a capacitor beat a battery on energy density, "said Perry."
"The combination of high energy density and high power density is uncommon in the capacitor world.""Researchers in Perry's lab have been making arrays of small sol-gel capacitors in the lab to gather information about the material's performance.
The devices are made on small substrates about an inch square.""What we see when we apply an electric field is that the polarization response
have longer battery life and generate less heat than existing mobile devices. The first supercomputers using silicon photonics--already under development at companies such as Intel
Graphene ink with binders usually conducts electricity better than binder-free ink, but only after the binder material,
With its high electrical conductivity, ability to store energy, and ultra-strong and lightweight structure, graphene has potential for many applications in electronics, energy, the environment,
and even medicine. Now a team of Northwestern University researchers has found a way to print three-dimensional structures with graphene nanoflakes.
and graphene's electrical conductivity most likely contributed to the scaffold's biological success."Cells conduct electricity inherently--especially neurons,
Light interaction with graphene produces particles called plasmons while light interacting with hbn produces phonons.
the plasmons and phonons can couple, producing a strong resonance. The properties of the graphene allow precise control over light,
#Researchers form complete nanobatteries inside nanopores Nanostructured batteries, when properly designed and built, offer promise for delivering their energy at much higher power and longer life than conventional technology.
To retain high energy density, nanostructures (such as nanowires) must be paced into dense"nanostructure forests, "producing 3-D nanogeometries in
Up to a billion of these nanopore batteries could fit in a grain of sand. The nanobatteries were fabricated by atomic layer deposition to make oxide nanotubes (for ion storage) inside metal nanotubes for electron transport, all inside each end of the nanopores.
they can transfer half their energy in just a 30 second charge or discharge time,
Research Insights Tiny batteries formed inside nanopores were used to demonstrate that properly scaled nanostructures can utilize the full theoretical capacity of the charge storage material
Science Impact These nanobatteries delivered their stored energy efficiently at high power (fast charge and discharge) and for extended cycling, demonstrating that precise nanostructures can be constructed to assess the fundamentals of ion
when placed in a magnetic field and generate negligible amounts of wasteful heat during energy harvesting, has been discovered by researchers at Temple University and the University of Maryland.
In the 1840s, physicist James Prescott Joule discovered that iron-based magnetic materials changed their shape but not their volume when placed in a magnetic field.
This phenomenon is referred to as"Joule Magnetostriction, "and since its discovery 175 years ago, all magnets have been characterized on this basis."We have discovered a new class of magnets,
or convert energy with minimal heat loss.""""The response of these magnets differs fundamentally from that likely envisioned by Joule,
"said Wuttig.""He must have thought that magnets respond in a uniform fashion.""Chopra and Wuttig discovered that
since they are limited by Joule magnetostriction. Actuation, even in two directions, requires bulky stacks of magnets,
These magnets could also find applications in efficient energy harvesting devices; compact micro-actuators for aerospace, automobile, biomedical, space and robotics applications;
This research has the potential to catapult sustainable energy-efficient materials in a very wide range of applications
"An interferogram showing the photoelectron energy vs. delay time between identical femtosecond pump and probe pulses,
The interferogram is taken from a movie of photoelectron energy vs. momentum with one frame corresponding to a 50-attosecond delay.
Detecting excitons in metals could provide clues on how light is converted into electrical and chemical energy in solar cells and plants.
soft and elastic batteries (Nanowerk News) A method for making elastic high-capacity batteries from wood pulp was unveiled by researchers in Sweden and the US.
foam-like battery material that can withstand shock and stress (Nature Communications, "Self-assembled three-dimensional and compressible interdigitated thin-film supercapacitors and batteries").
"This is a closeup of the soft battery, created with wood pulp nanocellulose. Image: Max Hamedi and Wallenberg Wood Science Center)" It is possible to make incredible materials from trees
and cellulose,"says Max Hamedi, who is a researcher at KTH and Harvard university. One benefit of the new wood-based aerogel material is that it can be used for three-dimensional structures."
"There are limits to how thin a battery can be, but that becomes less relevant in 3d,
"A 3d structure enables storage of significantly more power in less space than is possible with conventional batteries,
In fact, this type of structure and material architecture allows flexibility and freedom in the design of batteries,"Hamedi.
which adds ink that conducts electricity within the aerogel. You can coat the entire surface within."
Similarly, a single cubic decimeter of the battery material would cover most of a football pitch,
"Hamedi says the aerogel batteries could be used in electric car bodies, as well as in clothing, providing the garment has a lining.
Another partner is leading battery researcher, Professor Yi Cui from Stanford university y
#Intelligent bacteria for detecting disease Another step forward has just been taken in the area of synthetic biology.
and prevents penetration by gases and electrolytes. It provides protection against corrosion caused by aggressive aqueous solutions,
New materials for energy application, new concepts for medical surfaces, new surface materials for tribological systems and nano safety and nano bio.
Electrons that are driven toward the center absorb enough energy so that some of them emit blue light at double the frequency of the incoming infrared light.
It also has a number of unusual properties owing to the relationship between some of its energy states and its crystal structure.
This produces a plasma consisting of carbon ions, which is deposited as a coating on the workpiece in the vacuum.
The cylinder is converted evenly into plasma thanks to the scanning motion and rotation. To ensure a consistently smooth coating
a magnetic field guides the plasma and filters out any particles of dirt. The laser arc method can be used to deposit very thick ta-C coatings of up to 20 micrometers at high coating rates.
create jobs and stabilize energy prices involves converting the world's entire energy infrastructure to run on clean, renewable energy.
and the ways we currently consume energy, but indicate that the conversion is technically and economically possible through the wide-scale implementation of existing technologies."
who is also a senior fellow at the Stanford Woods Institute for the Environment and at the Precourt Institute for Energy."
"The study is published in the online edition of Energy and Environmental sciences("100%clean and renewable wind, water,
and sunlight (WWS) all-sector energy roadmaps for the 50 United states")."An interactive map summarizing the plans for each state is available at http://www. thesolutionsproject. org.
Jacobson and his colleagues started by taking a close look at the current energy demands of each state,
To create a full picture of energy use in each state, they examined energy usage in four sectors:
residential, commercial, industrial and transportation. For each sector, they then analyzed the current amount and source of the fuel consumed-coal oil, gas, nuclear,
if all fuel usage were replaced with electricity. This is a significantly challenging step-it assumes that all the cars on the road become electric,
and the energy savings would be significant.""When we did this across all 50 states, we saw a 39 percent reduction in total end-use power demand by the year 2050,
but the bulk is the result of replacing current sources and uses of combustion energy with electricity."
"The next step involved figuring out how to power the new electric grid. The researchers focused on meeting each state's new power demands using only the renewable energies-wind, solar, geothermal, hydroelectric,
and how many south-facing, non-shaded rooftops could accommodate solar panels. They developed and consulted wind maps
and determined whether local offshore wind turbines were an option. Geothermal energy was available at a reasonable cost for only 13 states.
The plan calls for virtually no new hydroelectric dams but does account for energy gains from improving the efficiency of existing dams.
The report lays out individual roadmaps for each state to achieve an 80 percent transition by 2030,
as they already generate nearly 30 percent of their electricity from wind power. California, which was the focus of Jacobson's second single-state roadmap to renewables after New york,
The plan calls for no more than 0. 5 percent of any state's land to be covered in solar panels or wind turbines.
The inhomogeneous electromagnetic field of the control signal's optical mode transmits a dipole moment to the cantilever,
impacting the dipole at the same time so that the cantilever starts to oscillate. The sinusoidally modulated control signal makes the cantilever oscillate at an amplitude of up to 20 nanometers.
Because the changes of the electromagnetic field in such systems are measured in tens of nanometers, researchers use the term"nanophotonics"-so the prefix"nano"is used not here just as a fad!
#'Nano-raspberries'could bear fruit in fuel cells (Nanowerk News) Researchers at the National Institute of Standards
which offers high surface area for catalyzing reactions in fuel cells. Individual particles are 3-4 nm in diameter
Curtin/NIST)( click on image to enlarge) The research could help make fuel cells more practical.
Nanoparticles can act as catalysts to help convert methanol to electricity in fuel cells. NIST's 40-minute process for making nano-raspberries, described in a new paper,*has several advantages.
For fuel cells, nanoparticles often are mixed with solvents to bind them to an electrode. To learn how such formulas affect particle properties,
For applications such as liquid methanol fuel cells, catalyst particles should remain separated and dispersed in the liquid,
Metals conduct electricity and heat very well, and they're very robust. Therefore, 3d printing in metals would allow manufacturing of entirely new devices and components,
High energy In this study, the researchers used a surprisingly high laser energy in comparison to earlier work,
In previous attempts, physicists used low laser energies. This allowed them to print smaller drops,
They had predicted previously this speed for different laser energies and materials. This means that the results can be translated readily to other metals as well.
One remaining problem is that the high laser energy also results in droplets landing on the substrate next to the desired location.
While the APSS own synchrotron is a powerful source for high-energy x-ray beams, the APS will not conduct single-shot single-particle imaging studies,
so the energy enough to break up the nanotubes into ribbons, but the details of the dynamics are difficult to monitor,
which can easily create self-ordered arrays of sub-20 nm features through simple spin-coating and plasma treatments.
"In addition, he wrote a review paper regarding the nanotechnology-based electronic devices in the June online issue of Advanced Materials entitled"Performance Enhancement of Electronic and Energy Devices via Block copolymer Self-Assembly
#Hematite're-growth'smoothes rough edges for clean energy harvest (Nanowerk News) Finding an efficient solar water splitting method to mine electron-rich hydrogen for clean
But by'regrowing'the mineral's surface, a smoother version of hematite doubled electrical yield, opening a new door to energy harvesting artificial photosynthesis,
whose research focuses on discovering new methods to generate clean energy.''This unassisted water splitting, which is very rare,
when enough heat or other energy is applied, the forces that bond the atoms together cause the atoms to vibrate
and spread the energy throughout the material, akin to how the vibration of a violin's string resonates throughout the body of the violin when played.
take out or move energy around inside a material. In particular, finding effective ways to remove heat energy is vital to the continued miniaturization of electronics.
and measure how much energy the electrons have transferred to the vibrating atoms. But it's difficult.
"Unlike a violin that sounds at the lightest touch, according to Natterer, phonons have a characteristic threshold energy.
unless they get just the right amount of energy, such as that supplied by the electrons in a scanning tunneling microscope (STM).
the unwanted signals also varied in energy, but the phonons remained fixed at their characteristic frequency.
ranging from the catalysts used for the generation of energy-dense fuels from sunlight and carbon dioxide, to how bridges and airplanes rust."
and causing atoms in the material to emit energy in the form of electrons rather than photons.
#New NMR tool helps scientists study elusive battery reaction (Nanowerk News) When working on a unique lithium-germanide battery with colleagues from the National University of Singapore,
scientists at Pacific Northwest National Laboratory encountered a catch-22: They knew an exciting reaction was occurring inside the battery that increased its energy storage capacity dramatically
-but they could not observe the reaction. The researchers needed to understand the process, but taking the battery apart caused the reaction to stop.
PNNL scientist Jian Zhi Hu displays a tiny experimental battery mounted in NMR apparatus used to observe the chemical reaction inside.
To solve the problem, the PNNL scientists encapsulated the battery cell in a plastic holder to allow magnetic waves to penetrate it
and developed a powerful nuclear magnetic resonance (NMR) technique to"see "and understand the electrochemical reactions taking place inside.
lithium-germanide battery and demonstrated how their unique NMR"camera"can be used to examine it
and gather data about reactions that can be observed only as they are happening inside a battery("Probing Lithium Germanide Phase Evolution and Structural Change in a Germanium-in-Carbon nanotube Energy storage system").
"Why It Matterslithium-ion batteries have many uses besides powering cell phones and laptops. Developing safer, more powerful cells with longer life is a worldwide challenge,
Germanium can take on more lithium during the reaction than other materials-making it a promising component for delivering higher battery capacity and superior discharge speeds,
but high battery performance resulting from its favorable uptake of lithium may be a factor in making lithium-germanide batteries attractive in the marketplace.
Scientists can create high-energy density batteries by using lithium with a number of different materials.
and reduce battery life and storage capacity. By using the NMR process to look inside the battery
and observe this reaction as it happened, the scientists found a way to protect the germanium from expanding
This technique significantly stabilizes battery performance. Without embedding germanium in carbon tubes, a battery performs well for a few charging-discharging cycles,
but fades rapidly after that. Using the"core-shell"structure, however, the battery can be discharged and charged thousands of times.
What's Next? Scientists are testing many different materials, including sulfur, cobalt, magnesium, manganese and others, to use with lithium in making batteries.
Many of these materials are potentially useful, but only those that are safe to use
The NMR technique used to enhance the performance of the lithium-germanide reaction may prove useful to scientists working on other types of batteries
"It's all about how to engineer the battery to make it safer and more powerful with a longer life,"said Jian Zhi Hu of PNNL, the lead NMR investigator and a collaborator in the project with Kian Ping Loh,
the leader of the team at the National University of Singapore where the battery was developed."
you have to understand the electrochemistry in the battery. Using NMR to understand hard-to-observe battery reaction phases is useful
when they exist only inside the battery. The procedure could lead to additional opportunities to collaborate with other researchers
#First solar cell made of highly ordered molecular frameworks (Nanowerk News) Researchers at KIT have developed a material suited for photovoltaics.
For the first time, a functioning organic solar cell consisting of a single component has been produced on the basis of metal-organic framework compounds (MOFS.
The material is highly elastic and might also be used for the flexible coating of clothes and deformable components.
"Organic solar cells made of metal-organic frameworks are highly efficient in producing charge carriers. Figure: Wll/KIT) We have opened the door to a new room,
suggest that the excellent properties of the solar cell result from an additional mechanism the formation of indirect band gaps that plays an important role in photovoltaics.
Nature uses porphyrines as universal molecules e g. in hemoglobin and chlorophyll, where these organic dyes convert light into chemical energy.
A metal-organic solar cell produced on the basis of this novel porphyrine-MOF is presented now by the researchers in the journal Angewandte Chemie (Applied Chemistry.
The clou is that we just need a single organic molecule in the solar cell, Wll says.
and take up electric charges. By means of a process developed at KIT, the crystalline frameworks grow in layers on a transparent,
Thanks to their mechanical properties, MOF thin films of a few hundred nanometers in thickness can be used for flexible solar cells or for the coating of clothing material or deformable components.
While the demand for technical systems converting sunlight into electricity is increasing, organic materials represent a highly interesting alternative to silicon that has to be processed at high costs before it can be used for the photoactive layer of a solar cell l
#Chemists devise technology that could transform solar energy storage (Nanowerk News) The materials in most of todays residential rooftop solar panels can store energy from the sun for only a few microseconds at a time.
A new technology developed by chemists at UCLA is capable of storing solar energy for up to several weeks an advance that could change the way scientists think about designing solar cells.
The findings are published June 19 in the journal Science("Long-lived photoinduced polaron formation in conjugated polyelectrolyte-fullerene assemblies".
"The scientists devised a new arrangement of solar cell ingredients, with bundles of polymer donors (green rods) and neatly organized fullerene acceptors (purple, tan.
The new design is inspired by the way that plants generate energy through photosynthesis. Biology does a very good job of creating energy from sunlight,
conventional rooftop solar cells use silicon, a fairly expensive material. There is currently a big push to make lower-cost solar cells using plastics, rather than silicon,
but todays plastic solar cells are relatively inefficient, in large part because the separated positive and negative electric charges often recombine before they can become electrical energy.
Modern plastic solar cells dont have well-defined structures like plants do because we never knew how to make them before,
Tolbert said. But this new system pulls charges apart and keeps them separated for days,
or even weeks. Once you make the right structure you can vastly improve the retention of energy.
The two components that make the UCLA-developed system work are a polymer donor and a nanoscale fullerene acceptor.
the process generates electrical energy. The plastic materials, called organic photovoltaics, are organized typically like a plate of cooked pasta a disorganized mass of long, skinny polymer spaghetti with random fullerene meatballs.
But this arrangement makes it difficult to get current out of the cell because the electrons sometimes hop back to the polymer spaghetti
The researchers are already working on how to incorporate the technology into actual solar cells. Yves Rubin, a UCLA professor of chemistry and another senior co-author of the study,
their designs are intended to be powered grid. When operating off the grid, these systems are not cost-effective,
essentially blocking disconnected, rural villages from using them. Wrights solution offers an alternative to grid power:
Shes designed a village-scale desalination system that runs on solar power. Since her system is powered by the sun,
and provide fracture energy dissipation by stick/slip interactions and frictional sliding of the platelets against each other."
#Sweeping lasers snap together nanoscale geometric grids Down at the nanoscale, where objects span just billionths of a meter,
Now, scientists at the U s. Department of energy's Brookhaven National Laboratory have developed a new technique to rapidly create nano-structured grids for functional materials with unprecedented versatility."
"We can fabricate multi-layer grids composed of different materials in virtually any geometric configuration,
"The results published online June 23 in the journal Nature Communications could transform the manufacture of high-tech coatings for anti-reflective surfaces, improved solar cells,
"Laser-assembled nanowires For the first step in grid construction, the team took advantage of their recent invention of laser zone annealing (LZA) to produce the extremely localized thermal spikes needed to drive ultra-fast self-assembly.
"To make these two-dimensional grids functional, the scientists converted the polymer base into other materials.
and overlap shapes the grid. We then apply the functional materials after each layer forms.
"For example, a single layer of platinum nanowires conducts electricity in only one direction, but a two-layer mesh conducts uniformly in all directions."
however, will require extremely low-power sensors that can run for months without battery changes or, even better,
that can extract energy from the environment to recharge. Last week, at the Symposia on VLSI Technology And circuits, MIT researchers presented a new power converter chip that can harvest more than 80 percent of the energy trickling into it
even at the extremely low power levels characteristic of tiny solar cells. Previous experimental ultralow-power converters had efficiencies of only 40 or 50 percent.
Moreover, the researcherschip achieves those efficiency improvements while assuming additional responsibilities. Where its predecessors could use a solar cell to either charge a battery
or directly power a device, this new chip can do both, and it can power the device directly from the battery.
All of those operations also share a single inductor the chip main electrical component which saves on circuit board space
the chip power consumption remains low. e still want to have battery-charging capability, and we still want to provide a regulated output voltage,
Ups and downs The circuit chief function is to regulate the voltages between the solar cell, the battery,
If the battery operates for too long at a voltage that either too high or too low, for instance, its chemical reactants break down,
since the rate at which it dissipates energy as heat is proportional to the square of the current.
and falls depends on the voltage generated by the solar cell, which is highly variable. So the timing of the switch throws has to vary, too.
whose selection is determined by the solar cell voltage. Once again, when the capacitor fills, the switches in the inductor path are flipped. n this technology space,
because there a fixed amount of energy that consumed by doing the work, says Brett Miwa,
the new design helps solve many key problems affecting mobile displays such as how to provide an always-on display function without requiring more frequent battery charging
Extending Power and Saving Energy Depending on how the display is used, the power savings can exceed current backlit technologies tenfold.
Overtext Web Module V3.0 Alpha
Copyright Semantic-Knowledge, 1994-2011