*** Bill Gates: Original Post From gatesnotes.com
The sun was out in full force the fall morning I arrived at Caltech to visit Professor Nate Lewis’s research laboratory. Temperatures in southern California had soared to 20 degrees above normal, prompting the National Weather Service to issue warnings for extreme fire danger and heat-related illnesses.
The weather was a fitting introduction to what I had come to see inside Nate’s lab—how we might be able to tap the sun’s tremendous energy to make fuels to power cars, trucks, ships, and airplanes.
Stepping into the lab cluttered with computer screens, jars of chemicals, beakers, and other equipment, Nate handed me a pair of safety goggles and offered some advice for what I was about to see. “Everything we do is simple in the end, even though there’s lots of complicated stuff,” he said.
What’s simple is the idea behind all of his team’s research: The sun is the most reliable, plentiful source of renewable energy we have. In fact, more energy from the sun hits the Earth in one hour than humans use in an entire year. If we can find cheap and efficient ways to tap just a fraction of its power, we will go a long way toward finding a clean, affordable, and reliable energy source for the future.
We are all familiar with solar panels, which convert sunlight into electricity. As solar panel costs continue to fall, it’s been encouraging to see how they are becoming a growing source of clean energy around the world. Of course, there’s one major challenge of solar power. The sun sets each night and there are cloudy days. That’s why we need to find efficient ways to store the energy from sunlight so it’s available on demand.
Batteries are one solution. Even better would be a solar fuel. Fuels have a much higher energy density than batteries, making it far easier to use for storage and transportation. For example, one ton of gasoline stores the same amount of energy as 60 tons of batteries. That’s why, barring a major breakthrough in battery technology, it’s hard to imagine flying from Seattle to Tokyo on a plug-in airplane.
I’ve written before about the need for an energy miracle to halt climate change and provide access to electricity to millions of the poorest families who live without it. Making solar fuel would be one of those miracles. It would solve the energy storage problem for when the sun isn’t shining. And it would provide an easy-to-use power source for our existing transportation infrastructure. We could continue to drive the cars we have now. Instead of running on fossil fuels from the ground, they would be powered by fuel made from sunlight. And because it wouldn’t contribute additional greenhouses gases to the atmosphere, it would be carbon neutral.
Imagining such a future is tantalizing. Realizing it will require a lot of hard work. No one knows if there’s a practical way to turn sunlight into fuel. Thanks to the U.S. Department of Energy, Nate and a group of other researchers around the U.S. are receiving research support to find out if it is possible.
We live in a time when new discoveries and innovations are so commonplace that it’s easy to take the cutting-edge research I saw at Caltech for granted. But most breakthroughs that improve our lives—from new health interventions to new clean energy ideas—get their start as government-sponsored research like Nate’s. If successful, that research leads to new innovations, that spawn new industries, that create new jobs, that spur economic growth. It’s impossible to overemphasize the importance of government support in this process. Without it, human progress would not come as far as it has.
Nate and his team are still at the first stage of this process. But they have reason to be optimistic about what lies ahead. After all, turning sunlight into chemical energy is what plants do every day. Through the process of photosynthesis, plants combine sunlight, water, and carbon dioxide to store solar energy in chemical bonds. At Nate’s lab, his team is working with the same ingredients. The difference is that they need to figure out how to do it even better and beat nature at its own game.
“We want to create a solar fuel inspired by what nature does, in the same way that man built aircraft inspired by birds that fly,” Nate said. “But you don’t build an airplane out of feathers. And we’re not going to build an artificial photosynthetic system out of chlorophylls and living systems, because we can do better than that.”
One of Nate’s students showed me how light can be used to split water into oxygen and hydrogen—a critical first step in the path to solar fuels. The next step would involve combining hydrogen with carbon dioxide to make fuels. Using current technologies, however, it is too costly to produce a fuel from sunlight. To make it cheaper, much more research needs to be done to understand the materials and systems that could create a dependable source of solar fuel.
One idea his team is working on is a kind of artificial turf made of plastic cells that could be easily rolled out to capture sunlight to make fuel. Each plastic cell would contain water, light absorbers, and a catalyst. The catalyst helps accelerate the chemical reactions so each cell can produce hydrogen or carbon-based fuels more efficiently. Unfortunately, the best catalysts are among the rarest and most expensive elements, like platinum. A key focus of Nate’s research is finding other catalysts that are not only effective and durable, but also economical.
Nate’s interest in clean energy research started during the oil crisis in the 1970s, when he waited for hours in gas lines with his dad. He says he knew then that he wanted to dedicate his life to energy research. Now, he is helping to train a new generation of scientists to help solve our world’s energy challenge. Seeing the number of young people working in Nate’s lab was inspiring. The pace of innovation for them is now much faster than ever before. “We do experiments now in a day that would once take a year or an entire Ph.D. thesis to do,” Nate said.
Still, I believe we should be doing a lot more. We need thousands of scientists following all paths that might lead us to a clean energy future. That’s why a group of investors and I recently launched Breakthrough Energy Ventures, a fund that will invest more than $1 billion in scientific discoveries that have the potential to deliver cheap and reliable clean energy to the world.
While we won’t be filling up our cars with solar fuels next week or next year, Nate’s team has already made valuable contributions to our understanding of how we might achieve this bold goal. With increased government and private sector support, we will make it possible for them to move ahead with their research at full speed.
This originally appeared on gatesnotes.com.
28 Feb 2017
Technology I: University of Central Florida
Leaving your phone plugged in for hours could become a thing of the past, thanks to a new type of battery technology that charges in seconds and lasts for over a week.
Watch the Video
While it probably won’t be commercially available for a years, the researchers said it has the potential to be used in phones, wearables and electric vehicles.
“If they were to replace the batteries with these supercapacitors, you could charge your mobile phone in a few seconds and you wouldn’t need to charge it again for over a week,” said Nitin Choudhary, a UCF postdoctoral associate, who conducted much of the research, published in the academic journal ACS Nano.
How does it work?
Unlike conventional batteries, supercapacitors store electricity statically on their surface which means they can charge and deliver energy rapidly. But supercapacitors have a major shortcoming: they need large surface areas in order to hold lots of energy.
To overcome the problem, the researchers developed supercapacitors built with millions of nano-wires and shells made from two-dimensional materials only a few atoms thick, which allows for super-fast charging. Their prototype is only about the size of a fingernail.
“For small electronic devices, our materials are surpassing the conventional ones worldwide in terms of energy density, power density and cyclic stability,” Choudhary said.
Cyclic stability refers to how many times a battery can be charged, drained and recharged before it starts to degrade. For lithium-ion batteries, this is typically fewer than 1,500 times.
Supercapacitors with two-dimensional materials can be recharged a few thousand times. But the researchers say their prototype still works like new even after being recharged 30,000 times.
Those that use the new materials could be used in phones, tablets and other electronic devices, as well as electric vehicles. And because they’re flexible, it could mean a significant development for wearables.
Technology II: Rice University
Identified Key Markets and Commercial Applications
- Medical Devices and Wearable Electronics
- Drone/Marine Batteries and Power Banks
- Powered Smart Cards and Motor Cycle/ EV Batteries
- Sensors & Power Units for the iOT (Internet of Things) [Flexible Form, Energy Dense]
The Coming Power Needs of the iOT
- The IoT is populated with billions of tiny devices.
- They’re smart.
- They’re cheap.
- They’re mobile.
- They need to communicate.
- Their numbers growing at 20%-30%/Year.
The iOT is Hungry for POWER! All this demands supercapacitors that can pack a lot of affordable power in very small volumes …Ten times more than today’s best supercapacitors can provide.
Highly Scalable – Energy Dense – Flexible Form – Rapid Charge
Problem 1: Current capacitors and batteries being supplied to the relevant markets lack the sustainable power density, discharge and recharge cycle, warranty life combined with a ‘flexible form factor’ to scale and satisfy the identified industry need for commercial viability & performance.
Solution I: (Minimal Value Product) Tenka is currently providing full, functional Super Capacitor prototypes to an initial customer in the Digital Powered Smart Card industry and has received two (2) phased Contingent Purchase Orders during the First Year Operating Cycle for 120,000 Units and 1,200,000 Units respectively.
Solution II: For Drone/ Marine Batteries – Power Banks & Medical Devices
- Double the current ‘Time Aloft’ (1 hour+)
- Reduces operating costs
- Marine batteries – Less weight, longer life, flex form
- Provides Fast Recharging, Extended Life Warranty.
- Full -battery prototypes being developed
Small batteries will be produced first for Powered Digital Smart Cards (In addition to the MVP Super Caps) solving packaging before scaling up drone battery operations. Technical risks are mainly associated with packaging and scaling.
The Operational Plan is to take full advantage of the gained ‘know how’ (Trade Secrets and Processes) of scaling and packaging solutions developed for the Powered Digital Smart Card and the iOT, to facilitate the roll-out of these additional Application Opportunities. Leveraging gained knowledge from operations is projected to significantly increase margins and profitability. We will begin where the Economies of Scale and Entry Point make sense (cents)!
“We are building and Energy Storage Company starting Small & Growing Big!”
Watch the YouTube Video
14 Feb 2017
Creating a Life-Saving, Blood-Repellent Super Material – Revolutionizing Medical Implants: Colorado State University
Goodbye Rejection – Implanted medical devices like stents, catheters, and titanium rods are essential, life-saving tools for patients around the world. Still, having a foreign object in the human body does pose its own risks – chiefly, having the body reject the object or increasing the risk of dangerous blood clots. A new collaboration between two distinct scientific disciplines is working toward making those risks a concern of the past.
Biomedical engineers and materials scientists from Colorado State University (CSU) ….
Florida State University College of Engineering Assistant Professor Shangchao Lin has published a new paper in the journal ACS Nano that predicts how an organic-inorganic hybrid material called organometal halide perovskites could be more mechanically flexible than existing silicon and other inorganic materials used for solar cells, thermoelectric devices and light-emitting diodes.
What if every vehicle, home appliance, heating system and light switch were connected to the Internet? Today, that’s not such a stretch of the imagination.
Modern cars, for instance, already have hundreds of sensors and multiple computers connected over an internal network. And that’s just one example of the 6.4 billion connected “things” in use worldwide this year, according to research by Gartner Inc. DHL and Cisco Systems offer even higher estimates—their 2015 Trend Report sets the current number of connected devices at about 15 billion, amidst industry expectations that the tally will increase to 50 billion by 2020.
29 Jan 2017
PEG-PDI, which incorporates a compound long used as a red dye, changes to greenish-blue with the addition of potassium superoxide as it converts the superoxide to dioxygen. Adding more further quenches the reactive oxygen species superoxide, turning the solution purple. Adding hydrogen peroxide in the last step clarifies the liquid, showing that a build-up of excess hydrogen peroxide can deactivate the structure. PEG-PDI, created at Rice University, shows potential as a biological antioxidant. Credit: Tour Group/Rice University
Treated particles of graphene derived from carbon nanotubes have demonstrated remarkable potential as life-saving antioxidants, but as small as they are, something even smaller had to be created to figure out why they work so well.
Researchers at Rice University, the McGovern Medical School at the University of Texas Health Science Center at Houston (UTHealth) and Baylor College of Medicine created single-molecule compounds that also quench damaging reactive oxygen species (ROS) but are far easier to analyze using standard scientific tools. The molecules may become the basis for new antioxidant therapies in their own right.
The research appears in the American Chemical Society journal ACS Nano.
The original compounds are hydrophilic carbon clusters functionalized with polyethylene glycol, known as PEG-HCCs and created by Rice and Baylor scientists five years ago. The particles help neutralize ROS molecules overexpressed by the body’s cells in response to an injury before they damage cells or cause mutations.
PEG-HCCs show promise for treating cancer, rebooting blood flow in the brain after traumatic injury and controlling chronic diseases.
The new particles, called PEG-PDI, consist of polyethylene glycol and perylene diimide, a compound used as a dye, the color in red car paint and in solar cells for its light-absorbing properties. Their ability to accept electrons from other molecules makes them functionally similar to PEG-HCCs.
They’re close enough to serve as an analog for experiments, according to Rice chemist James Tour, who led the study with University of Texas biochemist Ah-Lim Tsai.
The researchers wrote that the molecule is not only the first example of a small molecular analogue of PEG-HCCs, but also represents the first successful isolation of a PDI radical anion as a single crystal, which allows its structure to be captured with X-ray crystallography.
“This allows us to see the structure of these active particles,” Tour said. “We can get a view of every atom and the distances between them, and get a lot of information about how these molecules quench destructive oxidants in biological tissue.
“Lots of people get crystal structures for stable compounds, but this is a transient intermediate during a catalytic reaction,” he said. “To be able to crystallize a reactive intermediate like that is amazing.”
Antioxidant compounds mimic effective graphene agents, show potential for therapies
The crystal structure of PEG-PDI is achieved using cobaltocene as a reducing agent and omitting solvents and hydrogen atoms for clarity. Carbon atoms are gray, nitrogens are blue, oxygens red and cobalts purple. The molecules created by scientists at Rice University, the McGovern Medical School at the University of Texas Health Science Center at Houston and Baylor College of Medicine are efficient antioxidants and help scientists understand how larger nanoparticles quench damaging reactive oxygen species in the body. Credit: Tour Group
PEG-HCCs are about 3 nanometers wide and 30 to 40 nanometers long. By comparison, much simpler PEG-PDI molecules are less than a nanometer in width and length.
PEG-PDI molecules are true mimics of superoxide dismutase enzymes, protective antioxidants that break down toxic superoxide radicals into harmless molecular oxygen and hydrogen peroxide. The molecules pull electrons from unstable ROS and catalyze their transformation into less-reactive species.
Testing the PEG-PDI molecules can be as simple as putting them in a solution that contains reactive oxygen species molecules like potassium superoxide and watching the solution change color. Further characterization with electron paramagnetic resonance spectroscopy was more complicated, but the fact that it’s even possible makes them powerful tools in resolving mechanistic details, the researchers said.
Tour said adding polyethylene glycol makes the molecules soluble and also increases the amount of time they remain in the bloodstream. “Without PEG, they just go right out of the system through the kidneys,” he said.
When the PEG groups are added, the molecules circulate longer and continue to catalyze reactions.
He said PEG-PDI is just as effective as PEG-HCCs if measured by weight. “Because they have so much more surface area, PEG-HCC particles probably catalyze more parallel reactions per particle,” Tour said. “But if you compare them with PEG-PDI by weight, they are quite similar in total catalytic activity.”
Understanding the structure of PEG-PDI should allow researchers to customize the molecule for applications. “We should have a tremendous ability to modify the molecule’s structure,” he said. “We can add anything we want, exactly where we want, for specific therapies.”
The researchers said PEG-PDI may also be efficient metal- and protein-free catalysts for oxygen reduction reactions used in industry and essential to fuel cells. They are intrinsically more stable than enzymes and can function in much a wider pH range, Tsai said.
Co-author Thomas Kent, a professor of neurology at Baylor who has worked on the project from the start, noted small molecules have a better chance to get on the fast track to approval for therapy by the Food and Drug Administration than nanotube-based agents.
“A small molecule that is not derived from larger nanomaterial may have a better chance of approval to use in humans, assuming it is safe and effective,” he said.
Tour said PEG-PDI serves as a precise model for other graphene derivatives like graphene oxide and permits a more detailed study of graphene-based nanomaterials.
“Making nanomaterials smaller, from well-defined molecules, permits 150 years of synthetic chemistry methods to address the mechanistic questions within nanotechnology,” he said.
More information: Almaz S. Jalilov et al. Perylene Diimide as a Precise Graphene-Like Superoxide Dismutase Mimetic, ACS Nano (2017). DOI: 10.1021/acsnano.6b08211
Provided by: Rice University
29 Jan 2017
Read All The News Here: Genesis Nanotech: “Great Things from Small Things”
29 Jan 2017
A team of researchers at MIT has designed one of the strongest lightweight materials known, by compressing and fusing flakes of graphene, a two-dimensional form of carbon. The new material, a sponge-like configuration with a density of just 5 percent, can have a strength 10 times that of steel.
In its two-dimensional form, graphene is thought to be the strongest of all known materials. But researchers until now have had a hard time translating that two-dimensional strength into useful three-dimensional materials.
The new findings show that the crucial aspect of the new 3-D forms has more to do with their unusual geometrical configuration than with the material itself, which suggests that similar strong, lightweight materials could be made from a variety of materials by creating similar geometric features.
The findings are being reported today in the journal Science Advances, in a paper by Markus Buehler, the head of MIT’s Department of Civil and Environmental Engineering (CEE) and the McAfee Professor of Engineering; Zhao Qin, a CEE research scientist; Gang Seob Jung, a graduate student; and Min Jeong Kang MEng ’16, a recent graduate.
Other groups had suggested the possibility of such lightweight structures, but lab experiments so far had failed to match predictions, with some results exhibiting several orders of magnitude less strength than expected. The MIT team decided to solve the mystery by analyzing the material’s behavior down to the level of individual atoms within the structure. They were able to produce a mathematical framework that very closely matches experimental observations.
Two-dimensional materials—basically flat sheets that are just one atom in thickness but can be indefinitely large in the other dimensions—have exceptional strength as well as unique electrical properties. But because of their extraordinary thinness, “they are not very useful for making 3-D materials that could be used in vehicles, buildings, or devices,” Buehler says. “What we’ve done is to realize the wish of translating these 2-D materials into three-dimensional structures.”
The team was able to compress small flakes of graphene using a combination of heat and pressure. This process produced a strong, stable structure whose form resembles that of some corals and microscopic creatures called diatoms. These shapes, which have an enormous surface area in proportion to their volume, proved to be remarkably strong. “Once we created these 3-D structures, we wanted to see what’s the limit—what’s the strongest possible material we can produce,” says Qin. To do that, they created a variety of 3-D models and then subjected them to various tests. In computational simulations, which mimic the loading conditions in the tensile and compression tests performed in a tensile loading machine, “one of our samples has 5 percent the density of steel, but 10 times the strength,” Qin says.
Buehler says that what happens to their 3-D graphene material, which is composed of curved surfaces under deformation, resembles what would happen with sheets of paper. Paper has little strength along its length and width, and can be easily crumpled up. But when made into certain shapes, for example rolled into a tube, suddenly the strength along the length of the tube is much greater and can support substantial weight. Similarly, the geometric arrangement of the graphene flakes after treatment naturally forms a very strong configuration.
The new configurations have been made in the lab using a high-resolution, multimaterial 3-D printer. They were mechanically tested for their tensile and compressive properties, and their mechanical response under loading was simulated using the team’s theoretical models. The results from the experiments and simulations matched accurately.
The new, more accurate results, based on atomistic computational modeling by the MIT team, ruled out a possibility proposed previously by other teams: that it might be possible to make 3-D graphene structures so lightweight that they would actually be lighter than air, and could be used as a durable replacement for helium in balloons. The current work shows, however, that at such low densities, the material would not have sufficient strength and would collapse from the surrounding air pressure.
But many other possible applications of the material could eventually be feasible, the researchers say, for uses that require a combination of extreme strength and light weight. “You could either use the real graphene material or use the geometry we discovered with other materials, like polymers or metals,” Buehler says, to gain similar advantages of strength combined with advantages in cost, processing methods, or other material properties (such as transparency or electrical conductivity).
“You can replace the material itself with anything,” Buehler says. “The geometry is the dominant factor. It’s something that has the potential to transfer to many things.”
The unusual geometric shapes that graphene naturally forms under heat and pressure look something like a Nerf ball—round, but full of holes. These shapes, known as gyroids, are so complex that “actually making them using conventional manufacturing methods is probably impossible,” Buehler says. The team used 3-D-printed models of the structure, enlarged to thousands of times their natural size, for testing purposes.
For actual synthesis, the researchers say, one possibility is to use the polymer or metal particles as templates, coat them with graphene by chemical vapor deposit before heat and pressure treatments, and then chemically or physically remove the polymer or metal phases to leave 3-D graphene in the gyroid form. For this, the computational model given in the current study provides a guideline to evaluate the mechanical quality of the synthesis output.
The same geometry could even be applied to large-scale structural materials, they suggest. For example, concrete for a structure such a bridge might be made with this porous geometry, providing comparable strength with a fraction of the weight. This approach would have the additional benefit of providing good insulation because of the large amount of enclosed airspace within it.
Because the shape is riddled with very tiny pore spaces, the material might also find application in some filtration systems, for either water or chemical processing. The mathematical descriptions derived by this group could facilitate the development of a variety of applications, the researchers say.
More information: “The mechanics and design of a lightweight three-dimensional graphene assembly,” Science Advances, DOI: 10.1126/sciadv.1601536 , advances.sciencemag.org/content/3/1/e1601536
29 Jan 2017
The University Institute for Advanced Materials Research at the Universitat Jaume I (UJI) has participated in the European Project Sunflower, whose objective has been the development of organic photovoltaic materials less toxic and viable for industrial production.
A consortium of 17 research and business institutions has carried out this European project in the field of nanotechnology for four years and with an overall budget of 14.2 million euros, with funding of 10.1 million euros from the Seventh Framework Programme of the European Commission.
An introduction to Sunflower
Researchers at Sunflower have carried out several studies, among the most successful of which there are the design of an organic photovoltaic cell that can be printed and, consequently, has great versatility. In short, “we can assure that, thanks to these works, progress has been made in the achievement of solar cells with a good performance, low cost and very interesting architectural characteristics”, states the director of the University Institute for Advanced Materials Research (INAM) Juan Bisquert.
The goals of Sunflower were very ambitious, according to Antonio Guerrero, researcher at the Department of Physics integrated in the INAM, since it was intended “not only to improve the stability and efficiency of the photovoltaic materials, but also to reduce their costs of production”.
In fact, according to Guerrero, “the processes for making the leap from the laboratory to the industrial scale have been improved because, among others, non-halogenated solvents have been used that are compatible with industrial production methods and that considerably reduce the toxic loading of halogenates”.
“The involvement of our institute in these projects has a great interest because one of our priority lines of research is the new materials to develop renewable energies,” says Bisquert, who is also professor of Applied Physics. In addition, these consortia involve the work of academia and industry. According to the researcher, “the transfer of knowledge to society is favoured and, in this case, we demonstrate that organic materials investigated for twenty years are already close to become viable technologies”.
Change of use of plastic materials
The participation of UJI researchers at Sunflower has focused on “improving the aspect of chemical reactivity of materials or structural compatibility”, says Germà García, professor of Applied Physics and member of INAM.
“We have worked to move from the concepts of inorganic electronics to photovoltaic cells to the part of organic electronics,” he adds. The researchers wanted to take advantage of the faculties of absorption and conduction of plastic materials and to verify its capacity of solar production, an unusual use because normally they are used as an electrical insulation.
At UJI laboratories, they have studied the organic materials, very complex devices because they have up to eight nanometric layers. “We have made advanced electrical measurements to see where the energy losses were and thus to inform producers of materials and devices in order to improve the stability and efficiency of solar cells,” explains Guerrero.
Solar energy in everyday objects
“The potential applications of organic photovoltaic technology (OPV) are numerous, ranging from mobile consumer electronics to architecture,” says the project coordinator Giovanni Nisato, from the Swiss Centre for Electronics and Microtechnology (CSEM).
“Thanks to the results we have obtained, printed organic photovoltaics will become part of our daily lives, and will allow us to use renewable energy and respect the environment with a positive impact on our quality of life,” according to Nisato.
The European Sunflower project has been developed over 48 months with the main objective of extending the life and cost-efficiency of organic photovoltaic technology through better process control and understanding of materials. In addition, in the opinion of those responsible, the results of this research could double the share of renewable energy in its energy matrix, from 14% in 2012 to 27-30% by 2030. In fact, Sunflower has facilitated a significant increase in the use of solar energy incorporated in everyday objects.
The Sunflower consortium consists of 17 partners from across Europe: CSEM (Switzerland), DuPont Teijin Films UK Ltd (UK), Amcor Flexibles Kreuzlingen AG (Switzerland), Agfa-Gevaert NV (Belgium), Fluxim AG (Switzerland), University of Antwerp (Belgium), SAES Getters SpA (Italy), Consiglio Nazionale delle Ricerche-ISMN-Bologna (Italy), Hochschule für Life Sciences FHNW (Switzerland), Chalmers Tekniska Hoegskola AB (Sweden), Fraunhofer Institut der angewandten Forschung zur Foerderung @EV (Germany), Linköpings Universitet (Sweden), Universitat Jaume I (Spain), Genes’Ink (France), National Centre for Scientific Research (France), Belectric OPV GmbH (Germany) and Merck KGaA (Germany).
Meanwhile, the main lines of research at the INAM focus on new types of materials for clean energy devices, solar cells based on low cost compounds, such as perovskite and other organic compounds. Furthermore, INAM studies the production of fuels from sunlight, breaking water molecules and producing hydrogen and other catalytic materials in the chemical aspect, all of great importance in the context of international research.
Smart windows get darker to filter out the sun’s rays on bright days, and turn clear on cloudy days to let more light in. This feature can help control indoor temperatures and offers some privacy without resorting to aids such as mini-blinds.Now scientists report a new development in this growing niche: solar smart windows that can turn opaque on demand and even power other devices. The study appears in ACS Photonics (“Electrically Controllable Light Trapping for Self-Powered Switchable Solar Windows”).
Smart windows get darker to filter out the sun’s rays on bright days, and turn clear on cloudy days to let more light in. This feature can help control indoor temperatures and offers some privacy without resorting to mini-blinds. Now scientists report a new development in this growing niche: solar smart windows that can turn opaque on demand and even power other devices.
|Most existing solar-powered smart windows are designed to respond automatically to changing conditions, such as light or heat. But this means that on cool or cloudy days, consumers can’t flip a switch and tint the windows for privacy.|
|Also, these devices often operate on a mere fraction of the light energy they are exposed to while the rest gets absorbed by the windows. This heats them up, which can add warmth to a room that the windows are supposed to help keep cool. Jeremy Munday and colleagues wanted to address these limitations.|
|The researchers created a new smart window by sandwiching a polymer matrix containing microdroplets of liquid crystal materials, and an amorphous silicon layer — the type often used in solar cells — between two glass panes.
When the window is “off,” the liquid crystals scatter light, making the glass opaque. The silicon layer absorbs the light and provides the low power needed to align the crystals so light can pass through and make the window transparent when the window is turned “on” by the user.
|The extra energy that doesn’t go toward operating the window is harvested and could be redirected to power other devices, such as lights, TVs or smartphones, the researchers say.|
|Source: American Chemical Society|
|“By combining these two cells, the perovskite cell and the silicon cell, we are able to make much better use of the solar energy and achieve higher efficiencies than either cell on its own.”
Researchers at The Australian National University (ANU) have found a new way to fabricate high efficiency semi-transparent perovskite solar cells in a breakthrough that could lead to more efficient and cheaper solar electricity (Advanced Energy Materials, “Efficient Indium-Doped TiOxElectron Transport Layers for High-Performance Perovskite Solar Cells and Perovskite-Silicon Tandems”).
|Dr Tom White from the ANU Research School of Engineering said the new fabrication method significantly improved the performance of perovskite solar cells, which can combine with conventional silicon solar cells to produce more efficient solar electricity.|
|ANU Ph.D. student The Duong, Dr.Tom White and Ph.D. student Jun Peng.|
|He said perovskite solar cells were extremely good at making electricity from visible light – blue, green and red – while conventional silicon solar cells were more efficient at converting infrared light into electricity.|
|“The prospect of adding a few additional processing steps at the end of a silicon cell production line to make perovskite cells is very exciting and could boost solar efficiency from 25 per cent to 30 per cent,” Dr White said.|
|“By combining these two cells, the perovskite cell and the silicon cell, we are able to make much better use of the solar energy and achieve higher efficiencies than either cell on its own.”|
|While perovskite cells can improve efficiency, they are not yet stable enough to be used on rooftops. Dr White said the new fabrication technique could help develop more reliable perovskite cells.|
|The new fabrication method involves adding a small amount of the element indium into one of the cell layers during fabrication. That could increase the cell’s power output by as much as 25 per cent.|
|“We have been able to achieve a record efficiency of 16.6 per cent for a semi-transparent perovskite cell, and 24.5 per cent for a perovskite-silicon tandem, which is one of the highest efficiencies reported for this type of cell,” said Dr White.|
|Dr White said the research placed ANU in a small group of labs around the world with the capability to improve silicon solar cell efficiency using perovskites.|
|The development builds on the state-of-the-art silicon cell research at ANU and is part of a $12.2 million “High-efficiency silicon/perovskite solar cells” project led by University of New South Wales and supported by $3.6 million of funding from the Australian Renewable Energy Agency.|
|Research partners include Monash University, Arizona State University, Suntech R&D Australia Pty Ltd and Trina Solar.|
|Source: The Australian National University|
21 Nov 2016
Quantum computing is heralded as the next revolution in terms of global computing. Google, Intel and IBM are just some of the big names investing millions currently in the field of quantum computing which will enable faster, more efficient computing required to power the requirements of our future computing needs.
|Now a researcher and his team at Tyndall National Institute in Cork have made a ‘quantum leap’ by developing a technical step that could enable the use of quantum computers sooner than expected.|
|Conventional digital computing uses ‘on-off’ switches, but quantum computing looks to harness quantum state of matters – such as entangled photons of light or multiple states of atoms – to encode information. In theory, this can lead to much faster and more powerful computer processing, but the technology to underpin quantum computing is currently difficult to develop at scale.|
|Researchers at Tyndall have taken a step forward by making quantum dot light-emitting diodes (LEDs) that can produce entangled photons (whose actions are linked), theoretically enabling their use to encode information in quantum computing.|
|This is not the first time that LEDs have been made that can produce entangled photons, but the methods and materials described in the new paper (Nature Photonics, “Selective carrier injection into patterned arrays of pyramidal quantum dots for entangled photon light-emitting diodes”) have important implications for the future of quantum technologies, explains researcher Dr Emanuele Pelucchi, Head of Epitaxy and Physics of Nanostructures and a member of the Science Foundation Ireland-funded Irish Photonic Integration Centre (IPIC) at Tyndall National Institute in Cork.|
|Dr Emanuele Pelucchi.|
|“The new development here is that we have engineered a scalable array of electrically driven quantum dots using easily-sourced materials and conventional semiconductor fabrication technologies, and our method allows you to direct the position of these sources of entangled photons,” he says.|
|“Being able to control the positions of the quantum dots and to build them at scale are key factors to underpin more widespread use of quantum computing technologies as they develop.”|
|The Tyndall technology uses nanotechnology to electrify arrays of the pyramid-shaped quantum dots so they produce entangled photons. “We exploit intrinsic nanoscale properties of the whole “pyramidal” structure, in particular, an engineered self-assembled vertical quantum wire, which selectively injects current into the vicinity of a quantum dot,” explains Dr Pelucchi.|
|“The reported results are an important step towards the realization of integrated quantum photonic circuits designed for quantum information processing tasks, where thousands or more sources would function in unison.”|
|“It is exciting to see how research at Tyndall continues to break new ground, particularly in relation to this development in quantum computing. The significant breakthrough by Dr Pelucchi advances our understanding of how to harness the opportunity and power of quantum computing and undoubtedly accelerates progress in this field internationally. Photonics innovations by the IPIC team at Tyndall are being commercialized across a number sectors and as a result, we are directly driving global innovation through our investment, talent and research in this area,” said Dr Kieran Drain, CEO at Tyndall National Institute.|
|Source: Tyndall National Institute|