UC Berkley: Quantum Dot Solar Cell Creates 30-Fold Concentration: Low-Cost Solar Cells that use HE Section of Solar Spectrum

UC Berkley Solar Cells 090215 id41206By combining designer quantum dot light-emitters with spectrally matched photonic mirrors, a team of scientists with Berkeley Lab and the University of Illinois created solar cells that collect blue photons at 30 times the concentration of conventional solar cells, the highest luminescent concentration factor ever recorded. This breakthrough paves the way for the future development of low-cost solar cells that efficiently utilize the high-energy part of the solar spectrum.
“We’ve achieved a luminescent concentration ratio greater than 30 with an optical efficiency of 82-percent for blue photons,” says Berkeley Lab director Paul Alivisatos, who is also the Samsung Distinguished Professor of Nanoscience and Nanotechnology at the University of California Berkeley, and director of the Kavli Energy Nanoscience Institute (ENSI), was the co-leader of this research. “To the best of our knowledge, this is the highest luminescent concentration factor in literature to date.”
Luminescent solar concentrators featuring quantum dots and photonic mirrors
Luminescent solar concentrators featuring quantum dots and photonic mirrors suffer far less parasitic loss of photons than LSCs using molecular dyes as lumophores.
Alivisatos and Ralph Nuzzo of the University of Illinois are the corresponding authors of a paper in ACS Photonics describing this research entitled “Quantum Dot Luminescent Concentrator Cavity Exhibiting 30-fold Concentration”. Noah Bronstein, a member of Alivisatos’s research group, is one of three lead authors along with Yuan Yao and Lu Xu. Other co-authors are Erin O’Brien, Alexander Powers and Vivian Ferry.
The solar energy industry in the United States is soaring with the number of photovoltaic installations having grown from generating 1.2 gigawatts of electricity in 2008 to generating 20-plus gigawatts today, according to the U.S. Department of Energy (DOE). Still, nearly 70-percent of the electricity generated in this country continues to come from fossil fuels. SA Solar 5 191b940e-6e05-402a-bfbb-3e7be5f8a46f_16x9_600x338Low-cost alternatives to today’s photovoltaic solar panels are needed for the immense advantages of solar power to be fully realized. One promising alternative has been luminescent solar concentrators (LSCs).
Unlike conventional solar cells that directly absorb sunlight and convert it into electricity, an LSC absorbs the light on a plate embedded with highly efficient light-emitters called “lumophores” that then re-emit the absorbed light at longer wavelengths, a process known as the Stokes shift. This re-emitted light is directed to a micro-solar cell for conversion to electricity. Because the plate is much larger than the micro-solar cell, the solar energy hitting the cell is highly concentrated.
With a sufficient concentration factor, only small amounts of expensive III-V photovoltaic materials are needed to collect light from an inexpensive luminescent waveguide. However, the concentration factor and collection efficiency of the molecular dyes that up until now have been used as lumophores are limited by parasitic losses, including non-unity quantum yields of the lumophores, imperfect light trapping within the waveguide, and reabsorption and scattering of propagating photons.
“We replaced the molecular dyes in previous LSC systems with core/shell nanoparticles composed of cadmium selenide (CdSe) cores and cadmium sulfide (CdS) shells that increase the Stokes shift while reducing photon re-absorption,” says Bronstein.
“The CdSe/CdS nanoparticles enabled us to decouple absorption from emission energy and volume, which in turn allowed us to balance absorption and scattering to obtain the optimum nanoparticle,” he says. “Our use of photonic mirrors that are carefully matched to the narrow bandwidth of our quantum dot lumophores allowed us to achieve waveguide efficiency exceeding the limit imposed by total internal reflection.”
In their ACS Photonics paper, the collaborators express confidence that future LSC devices will achieve even higher concentration ratios through improvements to the luminescence quantum yield, waveguide geometry, and photonic mirror design.
The success of this CdSe/CdS nanoparticle-based LSC system led to a partnership between Berkeley Lab, the University of Illinois, Caltech and the National Renewable Energy Lab (NREL) on a new solar concentrator project. At the recent Clean Energy Summit held in Las Vegas, President Obama and Energy Secretary Ernest Moniz announced this partnership will receive a $3 million grant for the development of a micro-optical tandem LCS under MOSAIC, the newest program from DOE’s ARPA-E. MOSAIC stands for Micro-scale Optimized Solar-cell Arrays with Integrated Concentration.
The LCS work reported in this story was carried out through the U.S. Department of Energy’s Energy Frontier Research Center program and the National Science Foundation.
Source: By Lynn Yarris, Berkeley Lab

UC Berkley: Lawrence Berkley National Laboratory: Magnesium Nanoparticles Improve Hydrogen Storage

Hydorgen Storage 063015 id40624The dream of a cleaner, greener transportation future burns brightly in the promise of hydrogen-fueled, internal combustion engine automobiles. Modern-day versions of such vehicles run hot, finish clean and produce only pure water as a combustion byproduct.
But whether those vehicles ever cross over from the niche marketplace to become the mainstay of every garage may depend on how well we can address lingering technical and infrastructure hurdles that stand in the way of their widespread use. One of these is the fuel tank — how do you engineer them so that they can be more like gasoline tanks, which are relatively safe, easy to fill, carry you hundreds of miles and can be refueled again and again with no loss of performance?
This week in the journal Applied Physics Letters, from AIP Publishing (“Size-dependent mechanical properties of Mg nanoparticles used for hydrogen storage”), a team of researchers in the United States and China has taken a step toward that solution. They describe the physics of magnesium hydride, one type of material that potentially could be used to store hydrogen fuel in future automobiles and other applications. Using a technique known as in situ transmission electron microscopy, the team tested different sized nanoparticles of magnesium hydride to gauge their mechanical properties and discovered lessons on how one might engineer the nanoparticles to make them better.
Smaller Mg nanoparticles display better mechanical performance
Smaller Mg nanoparticles display better mechanical performance that is good for structural stability during cycling and also hydrogen storage kinetics. (Image: Qian Yu/Zhejiang University)
“Smaller particles have better mechanical properties, including better plastic stability,” said Qian Yu, the lead author on the paper. “Our work explained why.”
Yu is affiliated with Zhejiang University in Hangzhou, China; the University of California, Berkeley and Lawrence Berkeley National Laboratory.
Other collaborators on the work are affiliated with the University of Michigan in Ann Arbor; General Motors Research and Development Center in Warren, Michigan; and Shanghai Jiaotong University in Shanghai, China.
The Problem of Storing Hydrogen with Magnesium
Hydrogen storage for automobile engines is still something of an application in search of its technology. We know that the next generation of hydrogen fuel tanks will need to offer greater storage capacities and better gas exchange kinetics than existing models, but we don’t know exactly what it will take to deliver that.
One possibility is to use a material like magnesium hydride, long seen as a promising medium for storage. Magnesium readily binds hydrogen, and so the idea is that you could take a tank filled with magnesium, pump in hydrogen and then pump it out as needed to run the engine.
But this approach is hampered by slow kinetics of adsorption and desorption — the speed with which molecular hydrogen binds to and is released from the magnesium. This is ultimately tied to the how the material binds to hydrogen at the molecular level, and so in recent years researchers have sought to better engineer magnesium to achieve better kinetics.
Previous work had already shown that smaller magnesium nanoparticles have better hydrogen storage properties, but nobody understood why. Some thought it was primarily the greater overall magnesium surface area within the tank realized by milling smaller particles. But Yu and colleagues showed that it is also highly related to how the particles respond to deformation during cycles of fueling and emptying the tank.
Fuel cycles in a hydrogen tank introduce tremendous internal changes in pressure, which can deform the particles, cracking or degrading them. Smaller particles have greater plastic stability, meaning that they are more able to retain their structure even when undergoing deformation. This means that the smaller, more plastic magnesium nanoparticles can retain their structure longer and continue to hold hydrogen cycle after cycle.
But it turns out that in addition to greater plastic stability, the smaller particles also have less “deformation anisotropy” — a measure of how the magnesium nanoparticles all tend to respond, uniformly or not, across the entire tank. Deformation anisotropy is strongly reduced at nanoscales, Yu said, and because of this, smaller magnesium nanoparticles have more homogeneous dislocation activity inside, which offer more homogenously distributed diffusion path for hydrogen.
This suggests a path forward for making better hydrogen storage tanks, Yu said, by engineering them specifically to take advantage of greater homogeneous dislocation. Next they plan to do similar studies on hydrogen storage materials as they undergo fuel cycling, absorbing and desorbing hydrogen in the process.
Source: American Institute of Physics

Engineers create chameleon-like artificial ‘skin’ that shifts color on demand

Chamo Skin 150312100728-largeMarch 12, 2015
Source: The Optical Society
Borrowing a trick from nature, engineers have created an incredibly thin, chameleon-like material that can be made to change color — on demand — by simply applying a minute amount of force.

Developed by engineers from the University of California at Berkeley, this chameleon-like artificial “skin” changes color as a minute amount of force is applied.
Credit: The Optical Society (OSA)
Developed by engineers from the University of California at Berkeley, this chameleon-like artificial “skin” changes color as a minute amount of force is applied.

Credit: The Optical Society (OSA)

Borrowing a trick from nature, engineers from the University of California at Berkeley have created an incredibly thin, chameleon-like material that can be made to change color — on demand — by simply applying a minute amount of force.

This new material-of-many-colors offers intriguing possibilities for an entirely new class of display technologies, color-shifting camouflage, and sensors that can detect otherwise imperceptible defects in buildings, bridges, and aircraft.

“This is the first time anybody has made a flexible chameleon-like skin that can change color simply by flexing it,” said Connie J. Chang-Hasnain, a member of the Berkeley team and co-author on a paper published today in Optica, The Optical Society’s (OSA) new high-impact journal.

By precisely etching tiny features — smaller than a wavelength of light — onto a silicon film one thousand times thinner than a human hair, the researchers were able to select the range of colors the material would reflect, depending on how it was flexed and bent.

A Material that’s a Horse of a Different Color

The colors we typically see in paints, fabrics, and other natural substances occur when white, broad spectrum light strikes their surfaces. The unique chemical composition of each surface then absorbs various bands, or wavelengths of light. Those that aren’t absorbed are reflected back, with shorter wavelengths giving objects a blue hue and longer wavelengths appearing redder and the entire rainbow of possible combinations in between. Changing the color of a surface, such as the leaves on the trees in autumn, requires a change in chemical make-up.

Recently, engineers and scientists have been exploring another approach, one that would create designer colors without the use of chemical dyes and pigments. Rather than controlling the chemical composition of a material, it’s possible to control the surface features on the tiniest of scales so they interact and reflect particular wavelengths of light. This type of “structural color” is much less common in nature, but is used by some butterflies and beetles to create a particularly iridescent display of color.

Controlling light with structures rather than traditional optics is not new. In astronomy, for example, evenly spaced slits known as diffraction gratings are routinely used to direct light and spread it into its component colors. Efforts to control color with this technique, however, have proved impractical because the optical losses are simply too great.

The authors of the Optica paper applied a similar principle, though with a radically different design, to achieve the color control they were looking for. In place of slits cut into a film they instead etched rows of ridges onto a single, thin layer of silicon. Rather than spreading the light into a complete rainbow, however, these ridges — or bars — reflect a very specific wavelength of light. By “tuning” the spaces between the bars, it’s possible to select the specific color to be reflected. Unlike the slits in a diffraction grating, however, the silicon bars were extremely efficient and readily reflected the frequency of light they were tuned to.

Flexibility Is the Key to Control

Since the spacing, or period, of the bars is the key to controlling the color they reflect, the researchers realized it would be possible to subtly shift the period — and therefore the color — by flexing or bending the material.

“If you have a surface with very precise structures, spaced so they can interact with a specific wavelength of light, you can change its properties and how it interacts with light by changing its dimensions,” said Chang-Hasnain.

Earlier efforts to develop a flexible, color shifting surface fell short on a number of fronts. Metallic surfaces, which are easy to etch, were inefficient, reflecting only a portion of the light they received. Other surfaces were too thick, limiting their applications, or too rigid, preventing them from being flexed with sufficient control.

The Berkeley researchers were able to overcome both these hurdles by forming their grating bars using a semiconductor layer of silicon approximately 120 nanometers thick. Its flexibility was imparted by embedding the silicon bars into a flexible layer of silicone. As the silicone was bent or flexed, the period of the grating spacings responded in kind.

The semiconductor material also allowed the team to create a skin that was incredibly thin, perfectly flat, and easy to manufacture with the desired surface properties. This produces materials that reflect precise and very pure colors and that are highly efficient, reflecting up to 83 percent of the incoming light.

Their initial design, subjected to a change in period of a mere 25 nanometers, created brilliant colors that could be shifted from green to yellow, orange, and red — across a 39-nanometer range of wavelengths. Future designs, the researchers believe, could cover a wider range of colors and reflect light with even greater efficiency.

Chameleon Skin with Multiple Applications

For this demonstration, the researchers created a one-centimeter square layer of color-shifting silicon. Future developments would be needed to create a material large enough for commercial applications.

“The next step is to make this larger-scale and there are facilities already that could do so,” said Chang-Hasnain. “At that point, we hope to be able to find applications in entertainment, security, and monitoring.”

For consumers, this chameleon material could be used in a new class of display technologies, adding brilliant color presentations to outdoor entertainment venues. It also may be possible to create an active camouflage on the exterior of vehicles that would change color to better match the surrounding environment.

More day-to-day applications could include sensors that would change color to indicate that structural fatigue was stressing critical components on bridges, buildings, or the wings of airplanes.

“This is the first time anyone has achieved such a broad range of color on a one-layer, thin and flexible surface,” concluded Change-Hasnain. “I think it’s extremely cool.”

Story Source:

The above story is based on materials provided by The Optical Society. Note: Materials may be edited for content and length.

Journal Reference:

  1. Li Zhu, Jonas Kapraun, James Ferrara, Connie J. Chang-Hasnain. Flexible photonic metastructures for tunable coloration. Optica, 2015; 2 (3): 255 DOI: 10.1364/OPTICA.2.000255

Bacterial armor holds clues for self-assembling nanostructures

bacterial armorImagine thousands of copies of a single protein organizing into a coat of chainmail armor that protects the wearer from harsh and ever-changing environmental conditions. That is the case for many microorganisms. In a new study, researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) have uncovered key details in this natural process that can be used for the self-assembly of nanomaterials into complex two- and three-dimensional structures.

Caroline Ajo-Franklin, a chemist and synthetic biologist at Berkeley Lab’s Molecular Foundry, led this study in which high-throughput light scattering measurements were used to investigate the self-assembly of 2D nanosheets from a common bacterial surface layer (S-layer) protein. This protein, called “SbpA,” forms the protective armor for Lysinibacillus sphaericus, a soil bacterium used as a toxin to control mosquitoes. Their investigation revealed that play a key role in how this armor assembles. Two key roles actually.

“Calcium ions not only trigger the folding of the protein into the correct shape for nanosheet formation, but also serve to bind the nanosheets together,” Ajo-Franklin says. “By establishing and using light scattering as a proxy for SbpA nanosheet formation, we were able to determine how varying the concentrations of calcium ions and SbpA affects the size and shape of the S-layer armor.”

Details on this study have been published in the journal ACS Nano in a paper titled “Ion-Specific Control of the Self-Assembly Dynamics of a Nanostructured Protein Lattice.” Ajo-Franklin is the corresponding author. Co-authors are Behzad Rad, Thomas Haxton, Albert Shon, Seong-Ho Shin and Stephen Whitelam.

In the microbial world of bacteria and archaea, external threats abound. Their surrounding environment can transition from extreme heat to extreme cold, or from highly acidic to highly basic. Predators are everywhere. To protect themselves, many bacteria and archaea encase themselves within a shell of S-layer proteins. While scientists have known about this protective coating for many years, how it forms has been a mystery.

Ajo-Franklin and her colleagues have been exploring self-assembling proteins as a potential means of creating nanostructures with complex structure and function.

bacterial armor 2

The binding of calcium ions to SbpA proteins starts the process by which the SbpA self-assembles into nanosheets. Ca2+ binds to SbpA with an affinity of 67 μM. Credit: Image courtesy of Ajo-Franklin group, Berkeley Lab 

“At the Molecular Foundry, we’ve gotten really good at making nanomaterials into different shapes but we are still learning how to assemble these materials into organized structures,” she says. “S-layer proteins are abundant biological proteins known to self-assemble into 2D crystalline nanosheets with lattice symmetries and pore sizes that are about the same dimensions as quantum dots and nanotubes. This makes them a compelling model system for the creation of nanostructured arrays of organic and inorganic materials in a bottom-up fashion.”

In this latest study, light-scattering measurements were used to map out diagrams that revealed the relative yield of self-assembled nanosheets over a wide range of concentrations of SbpA and calcium ions. In addition, the effects of substituting manganese or barium ions for calcium ions were examined to distinguish between a chemically specific and generic divalent cation role for the calcium ions. Behzad Rad, the lead author of the ACS Nano paper, and co-workers followed light-scattering by light in the visible spectrum. They then correlated the signal to nanosheet formation by using electron microscopy and Small Angle X-ray Scattering (SAXS), a technology that can provide information on molecular assemblies in just about any type of solution. The SAXS measurements were obtained at the “SIBYLS beamline (12.3.1) of Berkeley Lab’s Advanced Light Source.

“We learned that only calcium ions trigger the SbpA self-assembly process and that the concentrations of calcium ions inside the cell are too low for nanosheets to form, which is a good thing for the bacterium,” says Rad. “We also found that the time evolution of the light scattering traces is consistent with the irreversible growth of sheets from a negligibly small nucleus. As soon as five calcium ions bind to a SbpA protein, the process starts and the crystal grows really fast. The small nucleus is what makes our light-scattering technique work.”

Ajo-Franklin, Rad and their co-authors believe their light-scattering technique is applicable to any type of protein that self-assembles into 2D nanosheets, and can be used to monitor growth from the nanometer to the micrometer scales.

Given the rugged nature of the S-layer proteins and their adhesive quality – bacteria use their S-layer armor to attach themselves to their surroundings – there are many intriguing applications awaiting further study.

“One project we’re exploring is using SbpA proteins to make adhesive nanostructures that could be used to remove metals and other contaminants from water,” Ajo-Franklin says. “Now that we have such a good handle on how SbpA proteins self-assemble, we’d like to start mixing and matching them with other molecules to create new and useful structures.”

Explore further: The ryanodine receptor—calcium channel in muscle cells

Solving an organic semiconductor mystery: DOE: Lawrence Berkley Nantional Laboratory

Naomi-Ginsberg-cartoonx250Organic semiconductors are prized for light-emitting diodes (LEDs), field effect transistors (FETs) and photovoltaic cells. As they can be printed from solution, they provide a highly scalable, cost-effective alternative to silicon-based devices. Uneven performances, however, have been a persistent problem. Scientists have known that the performance issues originate in the domain interfaces within organic semiconductor thin films, but have not known the cause. This mystery now appears to have been solved.

Naomi Ginsberg, a faculty chemist with the U.S. Dept. of Energy (DOE)’s Lawrence Berkeley National Laboratory and the Univ. of California (UC) Berkeley, led a team that used a unique form of microscopy to study the domain interfaces within an especially high-performing solution-processed organic semiconductor called TIPS-pentacene. She and her team discovered a cluttered jumble of randomly oriented nanocrystallites that become kinetically trapped in the interfaces during solution casting. Like debris on a highway, these nanocrystallites impede the flow of charge-carriers.

“If the interfaces were neat and clean, they wouldn’t have such a large impact on performance, but the presence of the nanocrystallites reduces charge-carrier mobility,” Ginsberg says. “Our nanocrystallite model for the interface, which is consistent with observations, provides critical information that can be used to correlate solution-processing methods to optimal device performances.”


Sketch of organic semiconductor thin film shows that the interfacial region between larger domains (blue and green) consists of randomly oriented small, nanocrystalline domains (purple).

Ginsberg, who holds appointments with Berkeley Lab’s Physical Biosciences Div. and its Materials Sciences Div., as well as UC Berkeley’s Depts. of Chemistry and Physics, is the corresponding author of a paper describing this research in Nature Communications.

Organic semiconductors are based on the ability of carbon to form larger molecules, such as benzene and pentacene, featuring electrical conductivity that falls somewhere between insulators and metals. Through solution-processing, organic materials can usually be fashioned into crystalline films without the expensive high-temperature annealing process required for silicon and other inorganic semiconductors. However, even though it has long been clear that the crystalline domain interfaces within semiconductor organic thin films are critical to their performance in devices, detailed information on the morphology of these interfaces has been missing until now.

“Interface domains in organic semiconductor thin films are smaller than the diffraction limit, hidden from surface probe techniques such as atomic force microscopy, and their nanoscale heterogeneity is not typically resolved using x-ray methods,” Ginsberg says. “Furthermore, the crystalline TIPS-pentacene we studied has virtually zero emission, which means it can’t be studied with photoluminescence microscopy.”

Ginsberg and her group overcame the challenges by using transient absorption (TA) microscopy, a technique in which femtosecond laser pulses excite transient energy states and detectors measure the changes in the absorption spectra. The Berkeley researchers carried out TA microscopy on an optical microscope they constructed themselves that enabled them to generate focal volumes that are a thousand times smaller than is typical for conventional TA microscopes. They also deployed multiple different light polarizations that allowed them to isolate interface signals not seen in either of the adjacent domains.

“Instrumentation, including very good detectors, the painstaking collection of data to ensure good signal-to-noise ratios, and the way we crafted the experiment and analysis were all critical to our success,” Ginsberg says. “Our spatial resolution and light polarization sensitivity were also essential to be able to unequivocally see a signature of the interface that was not swamped by the bulk, which contributes much more to the raw signal by volume.”

The methology developed by Ginsberg and her team to uncover structural motifs at hidden interfaces in organic semiconductor thin films should add a predictive factor to scalable and affordable solution-processing of these materials. This predictive capability should help minimize discontinuities and maximize charge-carrier mobility. Currently, researchers use what is essentially a trial-and-error approach, in which different solution casting conditions are tested to see how well the resulting devices perform.

“Our methodology provides an important intermediary in the feedback loop of device optimization by characterizing the microscopic details of the films that go into the devices, and by inferring how the solution casting could have created the structures at the interfaces,” Ginsberg says. “As a result, we can suggest how to alter the delicate balance of solution casting parameters to make more functional films.”

Source: Lawrence Berkeley National Laboratory

10 Unconventional Uses Of Nanotechnology ~ “Great Things from Small Things” ~ An Irish Blessing for 2015

1-Ceramics New-Featherweight-Champion-Nano-Ceramics_heroIt’s hard to envision the future without the presence of nanotechnologies. Manipulating matter at an atomic and sub-molecular level has paved the way for major breakthroughs in chemistry, biology, and medicine. Yet, the unfolding applications of nanotechnology are far broader and more diverse than what we’ve imagined.



Without the invention of the scanning tunneling microscope (STM) in the 1980s, the field of nanotechnology might have remained science fiction. With its atomic precision the STM has enabled physicists to study the structure of matter in a way that was impossible with conventional microscopes.

The astonishing potential of STM was demonstrated by researchers at IBM when they created A Boy and His Atom, which was the world’s smallest animated film. It was produced by moving individual atoms on a copper surface.

The 90-second movie depicts a boy made of carbon monoxide molecules playing with a ball, dancing, and bouncing on a trampoline. Consisting of 202 frames, the animation takes action in a space as tiny as 1/1000 the size of a single human hair. To make the movie, researchers utilized a unique feature that comes with the STM: an electrically charged and extremely sharp stylus with a tip made of one atom. The stylus is capable of sensing the exact positions of the carbon molecules on the animation surface (which is the sheet of copper in this case). Therefore, it can be used to create images of the molecules as well as move them into new positions.


9. Oil Recovery

9 Oil
The global expenditure for oil exploration has risen exponentially during the past decade. However, efficiency in oil recovery has remained a major issue. When petroleum companies shut down an oil well, less than half of the oil in the reservoir is extracted. The rest is left behind because it is trapped in the rock where it is too expensive to recover. Luckily, with help from nanotechnology, scientists in China have discovered a way to work around this.

The solution is enhancing an existing drilling technique. The original technique involves injecting water into the rock pores where oil is located. This displaces the oil and forces it out. However, this method reveals its limitation as soon as the oil in the easily reached pores has been extracted. By then, water begins emerging from the well instead of oil.

To prevent this, Chinese researchers Peng and Ming Yuan Li have come up with the idea of infusing the water with nanoparticles that can plug the passages between the rock pores. This method is intended to make the water take narrower paths into the pores that contain oil and force the oil out. With successful field studies conducted in China, this method has proven highly efficient in recovering the 50 percent of the black gold that otherwise remains out of reach.

8 High-Resolution Displays

8 High res
The images on computer screens are presented via tiny dots called pixels. Regardless of their sizes and shapes, the number of pixels on a screen has remained a determining factor of image quality. With traditional displays, however, more pixels meant larger and bulkier screens—an obvious limitation.

While companies were busy selling their colossal screens to consumers, scientists from Oxford University have discovered a way to create pixels that are just a few hundred nanometers across. This was achieved by exploiting the properties of a phase-change material called GST (a material found in thermal management products). In the experiment, the scientists used seven-nanometer-thick layers of GST sandwiched between transparent electrodes. Each layer—just 300 by 300 nanometers in size—acts as a pixel that can be electrically switched on and off. By passing electrical current through layers, the scientists were able to produce images with fair quality and contrast.

The nano-pixels will serve a variety of purposes where the conventional pixels have become impractical. For instance, their tiny size and thickness will make them a great choice for technologies such as smart glasses, foldable screens, and synthetic retinas. Another advantage of nano-pixel displays is their lower energy consumption. Unlike the existing displays that constantly refresh all pixels to form images, the GST-layer-based displays only refresh the part of the display that actually changes, saving power.seo-speed-of-light

7 Color-Changing Paint

7 paint
While experimenting on strings of gold nanoparticles, scientists at the University of California have stumbled upon an astonishing observation. They’ve noticed that the color of gold changes when a string of its particles is stretched or retracted, producing what one of the scientists described as a beautiful bright blue that morphs into purple and then red. The finding has inspired the scientists to create sensors out of gold nanoparticles that change colors when pressure is applied to them.

To produce the sensors, gold nanoparticles have to be added to a flexible polymer film. When the film is pressed, it stretches and causes particles to separate and the color to change. Pressing lightly turns the sensor purple while pressing harder turns it red. The scientists noticed this intriguing property not only in gold particles but also in silver where the particles change into yellow when stretched.

The sensors could serve a variety of purposes. For instance, they could be incorporated into furniture, such as couches or beds, to assess sitting or sleeping positions. Despite being made of gold, the sensor is tiny enough to overcome the cost issue.

6 Phone Charging

6 Smart phone
Whether it’s an iPhone, Samsung, or different type of phone, every smartphone that leaves the factory comes with two notorious downsides: battery life and the time it takes to recharge. While the first is still a universal problem, scientists from the city of Ramat Gan in Israel have managed to tackle the second problem by creating a battery that requires only 30 seconds to recharge.

The breakthrough was attributed to a project related to Alzheimer’s disease that was carried out by researchers from the University of Tel Aviv. The researchers discovered that the peptide molecules that shorten the brain’s neurons and cause disease have a very high capacitance (the ability to preserve electric charges). This finding has contributed to the foundation of StoreDot, a company that focuses on nanotechnologies that target consumer products. With help from researchers, StoreDot has developed NanoDots—technology that harnesses the peptides’ properties to improve the battery life of smartphones. The company demonstrated a prototype of its battery in Microsoft’s ThinkNext event. Using a Samsung Galaxy S3 phone, the battery was charged from zero to full in less than a minute.

5 Sophisticated Drug Delivery

5 Medicine
Treatments for diseases such as cancer can be prohibitively expensive and, in some cases, too late. Fortunately, several medical firms from around the world are researching cheap and effective ways of treating illnesses. Among them is Immusoft, a company that aims to revolutionize how medicines are delivered to our bodies.

Instead of spending billions of dollars on drugs and therapy programs, Immusoft believes that we can engineer our bodies to produce drugs by themselves. With help from the immune system, cells of a patient can be altered to receive new genetic information that allows them to make their own medicine. The genetic information can be delivered via nano-sized capsules injected into the body.

Cancer Nano 5-promisingnewThe new method hasn’t been tested out on a human patient yet. Nevertheless, Immusoft and other institutions have reported successful experiments conducted on mice. If proven effective on humans, the method will significantly reduce the treatment and therapy costs of cardiovascular diseases and various other illnesses.

4 Molecular Communication

4 Molecules
There are circumstances in which electromagnetic waves, the soul of global telecommunication, become unusable. Think of an electromagnetic pulse that could render communication satellites, and every form of technology relying on them, useless. We are quite familiar with such terrifying scenarios from doomsday movies. Furthermore, this issue has been contemplated for years by researchers from the University of Warwick in the United Kingdom and the York University in Canada before ultimately coming up with an unexpected solution.

The researchers observed how some animal species, particularly insects, employ pheromones to communicate across long distances. After collecting the data, they were able to develop a communication method in which messages are encoded in the molecules of evaporated alcohol. The researchers successfully demonstrated the new technique using rubbing alcohol as a signaling chemical and “O Canada” as their first message.

Two devices were employed with this method including a transmitter to encode and send the message and a receiver to decode and display it. The method works by keying in a text message on the transmitter using Arduino Uno (an open-source microcontroller) that comes with an LCD screen and buttons. The controller then converts the text input into a binary sequence which is read by an electronic sprayer containing the alcohol. Once the binary message is read, the sprayer converts it into a controlled set of sprays where “1” represents a spray and “0” equals no spray. The alcohol in the air is then detected by the receiver which consists of a chemical sensor and a microcontroller. The receiver reads and converts the binary data back to text before displaying it on a screen.

The researchers were able to send and receive the “O Canada” message across several feet of open space. As a result, a number of scientists have expressed confidence in the method. They believe it might be helpful in environments such as underground tunnels or pipelines where electromagnetic waves become useless.

3 Computer Storage

3 Computer
During the past few decades, computers have grown exponentially in both processing power and storage capacity. This phenomenon was accurately predicted by James Moore around 50 years ago and later became widely known as Moore’s Law. However, many scientists—including the physicist Michio Kaku—believe that Moore’s Law is falling apart. This is due to the fact that computer power cannot keep up with the exponential rise of the existing manufacturing technologies.

Though Kaku was emphasizing processing power, the same concept applies to storage capacity. Luckily, it’s not the end of the road. A team of researchers from RMIT University in Melbourne are now exploring the alternatives. Led by Dr. Sharath Sriram, the team is on the verge of developing storage devices that mimic the way the human brain stores information. The researchers took the first step and built a nano film that is chemically designed to preserve electric charges in on and off states. The film, which is 10,000 times thinner than a human hair, might become the cornerstone for developing memory devices that replicate the neural networks of the brain.

2 Nano Art

2 Art
The promising development of nanotechnology has earned a great deal of admiration from the scientific community. Nevertheless, breakthroughs in nanotechnology are no longer confined to medicine, biology, and engineering. Nano art is an emerging field that allows us to view the tiny world under the microscope from an entirely new perspective.

As its name implies, nano art is a combination of art and nanoscience practiced by a small number of scientists and artists. Among them is John Hart, a mechanical engineer from the University of Michigan, who made a nano portrait of President Barack Obama. The portrait, which was named Nanobama, was created to honor the President when he was a candidate during the 2008 presidential elections. Each face in Nanobama measures just half a millimeter across and is entirely sculpted from 150 nanotubes. To produce the portraits, Hart first created a line drawing of the iconic “Hope” poster. He then printed the drawing on a glass plate coated with the nanoparticles needed to grow nanotubes. Using a high-temperature furnace, it was only a matter of time before the portrait was ready for a photo shoot.

1 Record Breaking

1 Book
Humanity has always sought to build the strongest, fastest, and largest things. But, when it comes to building the smallest, nanotechnology emerges on the stage. Among the tiniest things ever created using nanotechnology is a book called Teeny Ted From Turnip which is currently regarded as the world’s smallest printed book. Produced in the Nano Imaging Laboratory at Simon Fraser University in Vancouver, Canada, the book measures just 70 micrometers by 100 micrometers and is made of letters carved on 30 crystalline silicon pages.

The book’s story, written by Malcolm Douglas Chaplin, features Teeny Ted and his triumph at the turnip contest at the annual county fair. Over 100 copies of the book have been published. But to buy one of them you will need a deep pocket—a single book costs over $15,000. An electron microscope will also be required to read it, adding even more to the cost.

We at Genesis Nanotechnology, Inc. would like to take this opportunity wish all of our Readers, Subscribers, Business Partners and Associates a most Blessed and Prosperous New Year!

It truly has been an amazing year for us. Every day the ‘World of Small Things’ has delivered new learning opportunities, a renewed sense of ‘wonderment’ in the unseen world around us and the opportunity to build new relationships with an ever expanding horizon of commercial opportunity.

And so .. a “Irish” Blessing for ALL of you for 2015

May the road rise up to meet you.
May the wind always be at your back.
May the sun shine warm upon your face,
and rains fall soft upon your fields.
And until we meet again,
May God hold you in the palm of His hand.

All the Best,

Bruce W. Hoy

CEO, Managing Partner

Genesis Nanotechnology, Inc.

Rice study fuels hope for natural gas cars

NG camry%20CNG%20hybridCars that run on natural gas are touted as efficient and environmentally friendly, but getting enough gas onboard to make them practical is a hurdle. A new study led by researchers at Rice University promises to help. Rather than shoehorn bulky high-pressure tanks like those used in buses and trucks into light vehicles, the Department of Energy (DOE) encourages scientists to look at new materials that can store compressed natural gas (CNG) at low pressure and at room temperature. Cage-like synthetic macromolecules called metal organic frameworks (MOFs) are among the candidates. Rice NG 1222_MDF-1-web

Examples of metal organic frameworks, which may be suitable for natural gas storage, were discovered through a computer algorithm developed at Rice University. The program explores possible combinations of components that may be used to synthesize the compounds. In these illustrations, molecules known as secondary building units (top left) and organic binding ligands, or linkers (top right) can be used in a chemical process to produce the metal organic framework seen at the bottom, according to the program. (Courtesy of the Deem Research Group/Rice University

MOFs are nanoscale compounds of metal ions or clusters known as secondary building units (SBUs) and organic binding ligands, or linkers. These linkers hold the SBUs together in a spongy network that can capture and store methane molecules in a tank under pressure. As the pressure is relieved, the network releases the methane for use. Because there are tens of thousands of possible MOFs, it’s a daunting task to synthesize them for testing. Researchers have turned to using computers to model candidates with the right qualities. A team led by Rice bioengineer Michael Deem went a step further; they used a custom algorithm to not only quickly design new MOF configurations able to store compressed natural gas — aka methane — with a high “deliverable capacity,” but ones that can be reliably synthesized from commercial precursor molecules. And here’s a handy bonus: The algorithm also keeps track of the routes to synthesis. Deem and his colleagues at Rice, the Lawrence Berkeley National Laboratory and the University of California-Berkeley reported their results this month in the American Chemical Society’s Journal of Physical Chemistry C.Rice logo_rice3 MOFs show potential for applications like drug delivery, sensing, purification and catalysis, but methane storage for transportation is high on the DOE’s wish list, Deem said. “MOFs are being commercialized for methane storage in vehicles now,” he said. The advantages to using MOF as a storage medium are many and start with increased capacity over the heavy, high-pressure cylinders in current use. The Rice study found 48 MOFs that beat the best currently available, a compound called MOF-5, by as much as 8 percent. The program adhered to standard DOE conditions that an ideal MOF would store methane at 65 bar (atmospheric pressure at sea level is one bar) and release it at 5.8 bar, all at 298 kelvins (about 77 degrees Fahrenheit). That pressure is significantly less than standard CNG tanks, and the temperature is far higher than liquid natural gas tanks that must be cooled to minus 260 degrees F. Lower pressures mean tanks can be lighter and made to fit cars better, Deem said. They may also offer the possibility that customers can tank up from household gas supply lines. The Deem group’s algorithm was adapted from an earlier project to identify zeolites. The researchers ran Monte Carlo calculations on nearly 57,000 precursor molecules, modifying them with synthetic chemistry reactions via the computer to find which would make MOFs with the best deliverable capacity — the amount of fuel that can be practically stored and released for use. “Our work differs from previous efforts because we’re searching the space of possible MOF linkers specifically for this deliverable capacity,” Deem said. The researchers hope to begin real-world testing of their best MOF models. “We’re very keen to work with experimental groups, and happy to collaborate,” Deem said. “We have joint projects underway, so we hope some of these predicted materials will be synthesized very soon.” Yi Bao, a graduate student in Deem’s lab at Rice’s BioScience Research Collaborative, is lead author of the paper. Co-authors are Richard Martin and Maciej Haranczyk of the Lawrence Berkeley National Laboratory and Cory Simon and Berend Smit of the University of California-Berkeley. Deem is chair of Rice’s Department of Bioengineering and the John W. Cox Professor of Biochemical and Genetic Engineering. The DOE Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences, supported the research. The researchers utilized the National Science Foundation-funded DAVinCi supercomputer administered by Rice’s Ken Kennedy Institute for Information Technology. Source: Rice University

MOF Slurry-Based Process May Revolutionize Carbon Capture

Slurry MOF NewsImage_31280Published on October 13, 2014 at 4:05 AM

Scientists from EPFL, UC Berkley and Beijing have developed a slurry-based process that can revolutionize carbon capture. The slurry, consisting of a porous powder suspended in glycol, offers the efficient large-scale implementation of a liquid while maintaining the lower costs and energy efficiency of solid carbon-capturing materials.

© 2014 EPFL Jamani Caillet

Carbon capture is a process by which waste carbon dioxide (CO2) released by factories and power plants is collected and stored away, in order to reduce global carbon emissions. There are two major ways of carbon capture today, one using powder-like solid materials which “stick” to CO2, and one using liquids that absorb it. Despite their potential environmental and energy benefits, current carbon capture strategies are prohibitive because of engineering demands, cost and overall energy-efficiency. Collaborating scientists from EPFL, UC Berkley and Beijing have combined carbon-capturing solids and liquids to develop a “slurry” that offers the best of both worlds: as a liquid it is relatively simple to implement on a large scale, while it maintains the lower costs and energy efficiency of a solid carbon-capturing material. The breakthrough method is published in Nature Communications.

The most common approach to carbon capture uses liquid amine solutions, which can absorb CO2 from the atmosphere. On a large scale, the system uses two columns, one for capturing CO2 and the other for releasing it from the liquid, in a process referred to as “regeneration”. For amine solutions, regeneration is the most energy-consuming part because the CO2 is so strongly bound to the amine molecules that it is necessary to actually boil them in order to separate them.

An alternative to liquids is to use solid materials known as “metal-organic frameworks” (MOFs). These are fine powders whose particles are made up of metal atoms that are connected into a 3D structure with organic linkers. Their surface is covered with nano-size pores that collect CO2 molecules. But despite its lower cost, as this method involves transporting solids it is very demanding in terms of engineering. Berend Smit, Director of the Energy Center at EPFL, explains: “Imagine trying to walk with a plateful of baby powder. It’s going to go everywhere, and it’s very difficult to control.”

Working with scientists from Beijing and UC Berkeley, Smit is a lead author on a breakthrough carbon-capture innovation that uses a mixture of solid and liquid in solution called a “slurry”. The solid part of the slurry is a MOF called ZIF-8, which is suspended in a 2-methylimidazole glycol liquid mixture.

“Why a slurry?” says Smit. “Because in the materials that are currently used for adsorption the pores are too large and the surrounding liquid would fill them, and not let them capture CO2 molecules. So here we looked at a material – ZIF-8 – whose pores are too small for the glycol’s molecules to fit, but big enough for capturing the CO2 molecules from flue gas.”

ZIF-8 is a good material for carbon-capturing slurries, because it displays excellent solution, chemical and thermal stability, which is important for repeated regeneration cycles. ZIF-8 crystals have narrow pores (3.4 Å in diameter) that are smaller than the diameter of glycol molecules (4.5 Å), preventing them from entering. Even though other liquids were tested in the design of the slurry, including ethanol, hexane, methylbenzene and tetrachloromethane, their molecules are small enough to enter the ZIF-8 pores and reduce its carbon capturing efficiency. In this respect, glycerol has so far been shown to be an ideal liquid.

The concept of the slurry comes from an idea of one of Smit’s former PhD students who is now a professor in Beijing, and it could be the key to large-scale implementation of carbon capture. “Pumping slurry is much easier than transporting a pile of baby powder,” says Smit. “And we can use the same technologies for heat integration as the liquid process.”

Because it combines the low cost and efficiency of nano-porous materials with the ease of a liquid-based separation process, the slurry successfully addresses these two main obstacles to the implementation of carbon capture in the real world. In addition, it shows exceptionally good separation from CO2, meaning that it doesn’t require excessive amounts of energy (e.g. boiling) in order to regenerate, which increases its overall energy efficiency.

The slurry offers a new template for developing similar combinations in the future. Following their successful proof-of-concept work, the research teams are now planning to test the ZIF-8/glycol slurry in the field.

This work represents a collaboration between EPFL, China University of Petroleum, University of California, Berkeley and Beijing University of Chemical Technology.


Liu H, Liu B, Lin L-C, Chen G, Wu Y, Wang J, Gao X, Lv Y, Pan Y, Zhang X, Zhang X, Yang L, Sun C, Smit B, Wang W. A hybrid absorption–adsorption method to efficiently capture carbon. Nature Communications DOI: 10.1038/ncomms6147

Source: http://actu.epfl.ch/