Posts belonging to Category Graphene



Nano-based Yarns Generate Electricity

An international research team led by scientists at The University of Texas at Dallas and Hanyang University in South Korea has developed high-tech yarns that generate electricity when they are stretched or twisted.

In a study published in the journal Science, researchers describe “twistronyarns and their possible applications, such as harvesting energy from the motion of ocean waves or from temperature fluctuations. When sewn into a shirt, these yarns served as a self-powered breathing monitor.

The easiest way to think of twistron harvesters is, you have a piece of yarn, you stretch it, and out comes electricity,” said Dr. Carter Haines BS’11, PhD’15, associate research professor in the Alan G. MacDiarmid NanoTech Institute at UT Dallas and co-lead author of the article. The article also includes researchers from South Korea, Virginia Tech, Wright-Patterson Air Force Base and China.

Coiled carbon nanotube yarns, created at The University of Texas at Dallas and imaged here with a scanning electron microscope, generate electrical energy when stretched or twisted.
The yarns are constructed from carbon nanotubes, which are hollow cylinders of carbon 10,000 times smaller in diameter than a human hair. The researchers first twist-spun the nanotubes into high-strength, lightweight yarns. To make the yarns highly elastic, they introduced so much twist that the yarns coiled like an over-twisted rubber band.

In order to generate electricity, the yarns must be either submerged in or coated with an ionically conducting material, or electrolyte, which can be as simple as a mixture of ordinary table salt and water.

Fundamentally, these yarns are supercapacitors,” said Dr. Na Li, a research scientist at the NanoTech Institute and co-lead author of the study. “In a normal capacitor, you use energy — like from a battery — to add charges to the capacitor. But in our case, when you insert the carbon nanotube yarn into an electrolyte bath, the yarns are charged by the electrolyte itself. No external battery, or voltage, is needed.

When a harvester yarn is twisted or stretched, the volume of the carbon nanotube yarn decreases, bringing the electric charges on the yarn closer together and increasing their energy, Haines said. This increases the voltage associated with the charge stored in the yarn, enabling the harvesting of electricity.

Source: http://www.utdallas.edu/

Green Solar Panels And Other Colors

Researchers from AMOLF, the University of Amsterdam (UvA) and the Energy Research Centre of the Netherlands (ECN) have developed a technology to create efficient bright green colored solar panels. Arrays of silicon nanoparticles integrated in the front module glass of a silicon heterojunction solar cell scatter a narrow band of the solar spectrum and create a green appearance for a wide range of angles. The remainder of the solar spectrum is efficiently coupled into the solar cell. The current generated by the solar panel is only  reduced by 10%. The realization of efficient colorful solar panels is an important step for the integration of solar panels into the built environment and landscape.
Photovoltaic
research has much focused on maximizing the electricity yield obtained from solar panels: nowadays, commercial panels have a maximum conversion efficiency from sunlight into electricity of around 22%. To reach such high efficiency, silicon solar cells have been equipped with a textured surface with an antireflection layer to absorb as much light as possible. This creates a dark blue or black appearance of the solar panels.

To create the colored solar panels the researchers have used the effect of Mie scattering, the resonant backscattering of light with a particular color by nanoparticles. They integrated dense arrays of silicon nanocylinders with a diameter of 100 nm in the top module cover slide of a high-efficiency silicon heterojunction solar cell. Due to the resonant nature of the light scattering effect, only the green part of the spectrum is reflected; the other colors are fully coupled into the solar cell. The current generated by the mini solar panel (0,7 x 0,7 cm2)  is only reduced by 10%. The solar panel appears green over a broad range of angles up to 75 degrees. The nanoparticles are fabricated using soft-imprint lithography, a technique that can readily be scaled up to large-area fabrication.
The light scattering effect due to Mie resonances is easily controllable: by changing the size of the nanoparticles the wavelength of the resonant light scattering can be tuned. Following this principle the researchers are now working to realize solar cells in other colors, and on a combination of different colors to create solar panels with a white appearance. For the large-scale application of solar panels, it is essential that their color can be tailored.

The new design was published online in the journal Applied Physics Letters.

Source: https://amolf.nl/

New WIFI Speeds Up To 300 Times Faster

Researchers at the Eindhoven University of Technology (Netherlands) say their new wireless network that uses harmless infrared rays will make wifi speeds up to 300 times faster.


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“What we are doing actually is using rays of light which convey the information in a wireless way, and each ray is acting as a very high capacity channel. It’s actually the same as an optical fibre without needing the fibre, and what we achieved up to this moment is 112 gigabits per second,” says Professor Ton Koonen, Eindhoven University of Technology.

That’s the equivalent data of three full-length movies being downloaded per second. Light antennas radiate multiple invisible wavelengths at various angles. If a user’s smartphone or tablet moves out of one antenna’s sightline, another takes over. Infrared wavelengths don’t go into your eyes, making them safe to use. The lack of moving parts makes the system maintenance and power-free. While each user gets their own antenna.

The big benefits we see of our technique is that you offer unshared capacity to each individual user, so you get a guaranteed capacity. Next to that you only get a beam if you need the traffic. So we’re not illuminating the whole place where maybe a single user is there. That means it’s much more power efficient. Another efficiency, another advantage, is that light doesn’t go through walls. So that means your communication is really confined to the particular room. Nobody can listen in from outside, so it offers you a lot of security,” explains rofessor Ton Koonen.
The team is seeking funding to help make the technology widespread within five years.

Source: http://www.reuters.com/

Biodegradable Car

TU/Ecomotive (Netherlands) says ‘Lina‘ is the world’s first car with a fully biocomposite body structure. The 4-seat e-car‘s chassis uses a combination of bio-composite and bio-plastic made from sugarbeet.

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It’s made of flax, the outside is made of flax fibres, together with polypropylene. It’s pressed and heated to make flat panels. In the middle you can see polylactic acid, the honeycomb structure of that material, which adds to the strength and weight savings of the sandwich panel. All structural parts of the car are made of this material,” says Yanic Van Riel, TU/Ecomotive.

The biocomposite has a similar strength-weight ratio to fibreglass, making the car light, greatly reducing battery size.

The car weighs only 310 kilograms which is really light for a car. That’s why we only need 30 kilograms of batteries. And on those 30 kilograms of battery packs we can drive around 100 kilometres, which is about four times more efficient than a BMW i3 right now and that’s in real city driving, so braking, stopping, accelerating, not just like the most optimal driving,” explains Yanic Van Riel.

Lina has a top speed of around 50 miles per hour. Electronic features include NFCnearfield communication technology.  “We can open our doors with NFC technology and a car will immediately recognise who is driving it. So if I’m opening it, it will save all the data from me and if someone else opens it, it will save his data. In that way we can use this car for carsharing apps, which other companies are creating. Also we have a hood system which projects the speed and all the information of the car into the front window, so we can see it through the window and still see the road, so it’s more safe,” adds Noud Van De Gevel, TU/Ecomotive.

The team hopes the prototype will soon be declared roadworthy, allowing it to be tested on Eindhoven city streets.

Source: http://tuecomotive.nl/

Pilotless Cargo Flights By 2025

Pilotless planes would save airlines $35bn (£27bn) a year and could lead to substantial fare cuts – if passengers were able to stomach the idea of remote-controlled flying, according to new research. The savings for carriers could be huge, said investment bank UBS, even though it may take until the middle of the century for passengers to have enough confidence to board a pilotless plane. UBS estimated that pilots cost the industry $31bn a year, plus another $3bn in training, and that fully automated planes would fly more efficiently, saving another $1bn a year in fuel.

Passengers could benefit from a reduction in ticket prices of about a tenth, the report said. “The average percentage of total cost and average benefit that could be passed onto passengers in price reduction for the US airlines is 11%,” it said, although the savings in Europe would be less, at 4% on average but rising to 8% at RyanairAircraft costs and fuel make up a much larger proportion of costs at airlines than pilot salaries, but UBS said profits at some major airlines could double if they switched to pilotless.

More than half of the 8,000 people UBS surveyed, however, said they would refuse to travel in a pilotless plane, even if fares were cut. “Some 54% of respondents said they were unlikely to take a pilotless flight, while only 17% said they would likely undertake a pilotless flight. Perhaps surprisingly, half of the respondents said that they would not buy the pilotless flight ticket even if it was cheaper,” the report said. It added, however, that younger and more educated respondents were more willing to fly on a pilotless plane. “This bodes well for the technology as the population ages,” it said.

Source: https://www.theguardian.com/

No More Batteries For Cellphones

University of Washington (UW) researchers have invented a cellphone that requires no batteries — a major leap forward in moving beyond chargers, cords and dying phones. Instead, the phone harvests the few microwatts of power it requires from either ambient radio signals or light.

The team also made Skype calls using its battery-free phone, demonstrating that the prototype made of commercial, off-the-shelf components can receive and transmit speech and communicate with a base station.

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We’ve built what we believe is the first functioning cellphone that consumes almost zero power,” said co-author Shyam Gollakota, an associate professor in the Paul G. Allen School of Computer Science & Engineering at the UW. “To achieve the really, really low power consumption that you need to run a phone by harvesting energy from the environment, we had to fundamentally rethink how these devices are designed.”

The team of UW computer scientists and electrical engineers eliminated a power-hungry step in most modern cellular transmissionsconverting analog signals that convey sound into digital data that a phone can understand. This process consumes so much energy that it’s been impossible to design a phone that can rely on ambient power sources. Instead, the battery-free cellphone takes advantage of tiny vibrations in a phone’s microphone or speaker that occur when a person is talking into a phone or listening to a call.

An antenna connected to those components converts that motion into changes in standard analog radio signal emitted by a cellular base station. This process essentially encodes speech patterns in reflected radio signals in a way that uses almost no power. To transmit speech, the phone uses vibrations from the device’s microphone to encode speech patterns in the reflected signals. To receive speech, it converts encoded radio signals into sound vibrations that that are picked up by the phone’s speaker. In the prototype device, the user presses a button to switch between these two “transmitting” and “listening” modes.

The new technology is detailed in a paper published July 1 in the Proceedings of the Association for Computing Machinery on Interactive, Mobile, Wearable and Ubiquitous Technologies.

Source: http://www.washington.edu/
AND
http://www.reuters.com/

Hyperloop, Train Of The Future, Nearly Hits 200 mph

After announcing “the successful completion of the world’s first full systems Hyperloop test in a vacuum environment” last month, Hyperloop One is now releasing the details of a new test with their actual pod in their vacuum test tube.

They achieved a new top speed of 192 mph (310 km an hour).

Shervin Pishevar, Executive Chairman and Co-founder of Hyperloop One, made the announcement

This is the beginning, and the dawn of a new era of transportation. We’ve reached historic speeds of 310 km an hour, and we’re excited to finally show the world the XP-1 going into the Hyperloop One tube. When you hear the sound of the Hyperloop One, you hear the sound of the future.”

It’s still not on par with the ~700 mph speed that they originally planned the system to enable, but the full-scale 500-meter test track is shorter than the previously announced 1-mile long tube and it is still early in their development process.

They achieved the new top speed on just 300 meters of propulsion ramp, which is impressive, and they increased the speed by 2.7x over last month’s first test. The company disclosed that “all components of the system were successfully tested, including the highly efficient electric motor, advanced controls and power electronics, custom magnetic levitation and guidance, pod suspension and vacuum system.”

Source: https://hyperloop-one.com/
AND
https://electrek.co/

By 2025 Renewables Will Power 67 Percent Of South Australia

Declining renewables and energy storage costs will increasingly squeeze out gas-fired generation in South Australia as early as 2025, a joint research report conducted by Wood Mackenzie and GTM Research shows. The South Australia experience is noteworthy in a global power mix set to increasingly shift to renewable energy. South Australia retired its last coal plant in 2016 and is projected to have installed renewable energy capacity exceed its peak demand by 2020.

By 2025, wind, solar and battery costs will fall by 15 percent, 25 percent and 50 percent respectively. By then, renewables and batteries could offer a lower cost alternative to combined-cycle gas turbine plants, which are commonly used to manage base load power generation in South Australia. Meanwhile by 2035, renewables and batteries will provide a commercial solution for both base loads and peak loads. As a consequence, gas will increasingly be used just for emergency back-up.

One determining factor is the rate with which battery charging costs declines. By 2025, we expect battery charging cost to decrease as off-peak prices will gradually be set by excess wind generation. Battery storage then becomes a potential solution for managing peak loads,” said Bikal Pokharel, principal analyst for Wood Mackenzie‘s Asia-Pacific power and renewables .
By 2025 it’s expected that 67 percent of South Australia’s power capacity will come from renewables. Gas demand in the power sector will then decline by 70 percent.

Currently, South Australia’s peak loads are managed by open-cycle gas turbine (OCGT) plants. But by 2025, battery storage would be cheaper than OCGTs in managing peak loads even at gas price of A$7/mmbtu. OCGTs would then be relegated as emergency back-ups.”

Source: https://www.woodmac.com/

Cheap, Robust Catalyst Splits Water Into Hydrogen And Oxygen

Splitting water into hydrogen and oxygen to produce clean energy can be simplified with a single catalyst developed by scientists at Rice University and the University of Houston. The electrolytic film produced at Rice and tested at Houston is a three-layer structure of nickel, graphene and a compound of iron, manganese and phosphorus. The foamy nickel gives the film a large surface, the conductive graphene protects the nickel from degrading and the metal phosphide carries out the reactionRice chemist Kenton Whitmire and Houston electrical and computer engineer Jiming Bao and their labs developed the film to overcome barriers that usually make a catalyst good for producing either oxygen or hydrogen, but not both simultaneously.

A catalyst developed by Rice University and the University of Houston splits water into hydrogen and oxygen without the need for expensive metals like platinum. This electron microscope image shows nickel foam coated with graphene and then the catalytic surface of iron, manganese and phosphorus

Regular metals sometimes oxidize during catalysis,” Whitmire said. “Normally, a hydrogen evolution reaction is done in acid and an oxygen evolution reaction is done in base. We have one material that is stable whether it’s in an acidic or basic solution.

The discovery builds upon the researchers’ creation of a simple oxygen-evolution catalyst revealed earlier this year. In that work, the team grew a catalyst directly on a semiconducting nanorod array that turned sunlight into energy for solar water splittingElectrocatalysis requires two catalysts, a cathode and an anode. When placed in water and charged, hydrogen will form at one electrode and oxygen at the other, and these gases are captured. But the process generally requires costly metals to operate as efficiently as the Rice team’s catalyst.

The standard for hydrogen evolution is platinum,” Whitmire explained. “We’re using Earth-abundant materials — iron, manganese and phosphorus — as opposed to noble metals that are much more expensive.

The robust material is the subject of a paper in Nano Energy.

Source: http://news.rice.edu/

New Solar System Produces 50 Percent More Energy

A concentrating photovoltaic system (CPV) with embedded microtracking can produce over 50 percent more energy per day than standard silicon solar cells in a head-to-head competition, according to a team of engineers who field tested a prototype unit over two sunny days last fall.

Solar cells used to be expensive, but now they’re getting really cheap,” said Chris Giebink, Charles K. Etner Assistant Professor of Electrical Engineering, Penn State. “As a result, the solar cell is no longer the dominant cost of the energy it produces. The majority of the cost increasingly lies in everything else — the inverter, installation labor, permitting fees, etc. — all the stuff we used to neglect.

This changing economic landscape has put a premium on high efficiency. In contrast to silicon solar panels, which currently dominate the market at 15 to 20 percent efficiency, concentrating photovoltaics focus sunlight onto smaller, but much more efficient solar cells like those used on satellites, to enable overall efficiencies of 35 to 40 percent. Current CPV systems are large — the size of billboards — and have to rotate to track the sun during the day. These systems work well in open fields with abundant space and lots of direct sun.

What we’re trying to do is create a high-efficiency CPV system in the form factor of a traditional silicon solar panel,” said Giebink.

Source: http://news.psu.edu/

Move And Produce Electricity To Power Your Phone

Imagine slipping into a jacket, shirt or skirt that powers your cell phone, fitness tracker and other personal electronic devices as you walk, wave and even when you are sitting down. A new, ultrathin energy harvesting system developed at Vanderbilt University’s Nanomaterials and Energy Devices Laboratory has the potential to do just that. Based on battery technology and made from layers of black phosphorus that are only a few atoms thick, the new device generates small amounts of electricity when it is bent or pressed even at the extremely low frequencies characteristic of human motion.

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In the future, I expect that we will all become charging depots for our personal devices by pulling energy directly from our motions and the environment,” said Assistant Professor of Mechanical Engineering Cary Pint, who directed the research.
This is timely and exciting research given the growth of wearable devices such as exoskeletons and smart clothing, which could potentially benefit from Dr. Pint’s advances in materials and energy harvesting,” observed Karl Zelik, assistant professor of mechanical and biomedical engineering at Vanderbilt, an expert on the biomechanics of locomotion who did not participate in the device’s development.

Doctoral students Nitin Muralidharan and Mengya Lic o-led the effort to make and test the devices. When you look at Usain Bolt, you see the fastest man on Earth. When I look at him, I see a machine working at 5 Hertz, said Muralidharan.

The new energy harvesting system is described in a paper titled “Ultralow Frequency Electrochemical Mechanical Strain Energy Harvester using 2D Black Phosphorus Nanosheets” published  by the journal ACS Energy Letters.

Source: https://news.vanderbilt.edu/

Nanoweapons Against North Korea

Unless you’re working in the field, you probably never heard about U.S. nanoweapons. This is intentional. The United States, as well as Russia and China, are spending billions of dollars per year developing nanoweapons, but all development is secret. Even after Pravda.ru’s June 6, 2016 headline, “US nano weapon killed Venezuela’s Hugo Chavez, scientists say,” the U.S. offered no response.

Earlier this year, May 5, 2017, North Korea claimed the CIA plotted to kill Kim Jong Un using a radioactive nano poison, similar to the nanoweapon Venezuelan scientists claim the U.S. used to assassinate former Venezuelan President Hugo Chavez. All major media covered North Korea’s claim. These accusations are substantial, but are they true? Let’s address this question.

Unfortunately, until earlier this year, nanoweapons gleaned little media attention. However, in March 2017 that changed with the publication of the book, Nanoweapons: A Growing Threat to Humanity (2017 Potomac Books), which inspired two articles. On March 9, 2017, American Security Today published “Nanoweapons: A Growing Threat to Humanity – Louis A. Del Monte,” and on March 17, 2017, CNBC published “Mini-nukes and mosquito-like robot weapons being primed for future warfare.” Suddenly, the genie was out of the bottle. The CNBC article became the most popular on their website for two days following its publication and garnered 6.5K shares. Still compared to other classes of military weapons, nanoweapons remain obscure. Factually, most people never even heard the term. If you find this surprising, recall most people never heard of stealth aircraft until their highly publicized use during the first Iraq war in 1990. Today, almost everyone that reads the news knows about stealth aircraft. This may become the case with nanoweapons, but for now, it remains obscure to the public.

Given their relative obscurity, we’ll start by defining nanoweapons. A nanoweapon is any military weapon that exploits the power of nanotechnology. This, of course, begs another question: What is nanotechnology? According to the United States National Nanotechnology Initiative’s website, nano.gov, “Nanotechnology is science, engineering, and technology conducted at the nanoscale, which is about 1 to 100 nanometers.” To put this in simple terms, the diameter of a typical human hair equals 100,000 nanometers. This means nanotechnology is invisible to the naked eye or even under an optical microscope.

Source: http://www.huffingtonpost.com/