Articles from July 2017

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.


Multi-AntiOxidant Nanoparticles Fight Sepsis

With an incidence of 31.5 million worldwide and a mortality of around 17%, sepsis remains the most common cause of death in hospitalized patients, even in industrialized countries where antibiotics and critical care facilities are readily available. While this disease begins as a serious infection, sepsis‘ life-threatening organ failure is due to an excessive inflammatory response.

By overproducing oxygen free radicals, the immunity of the host itself paradoxically leads to an increase in morbidity and mortality. A team of researchers from Center for Nanoparticle Research, within the  (IBS), with colleagues from the Seoul National University Hospital synthesized nanoparticles with superior antioxidant properties to treat sepsis in rats and mice by removing harmful oxygen radicals and reducing inflammatory responses.

Under normal physiological conditions, oxygen radicals, also called reactive oxygen species (ROS), are created as by-products of several cellular reactions and their concentration is counterbalanced by antioxidant enzymes, such as superoxide dismutase (SOD) and catalase (CAT). However in patients with severe infections, the production of ROS as well as reactive nitrogen species (RNS), increases dramatically, while the body’s antioxidant capacity may be compromised. As a consequence, the ROS and RNS accumulation can lead to damages to DNA, proteins, and lipid membranes.

All major diseases are related to ROS,” explains HYEON Taeghwan, the director of the Center for Nanoparticle Research. “Cellular damage caused by ROS has been found not only in sepsis, but also in cancer, diabetes, cardiovascular disease, atherosclerosis, and neurodegenerative diseases, just to name a few.”

Ceria nanoparticles replace the function of antioxidant enzymes. Cerium trivalent ions (Ce3+) play a decisive role in eliminating ROS. Thanks to the addition of zirconium ions, the scientists could create a new type of nanoparticles, named 7CZ (containing 70% Ce ions and 30% Zr ions), with optimized nanoparticle size and Ce3+ content. The nanoparticles described in this study are smaller, just two nanometers in size. Moreover, they have a higher percent of Ce3+. When tested in mice with sepsis, the survival rate increased 2.5 fold in the 7CZ NP-treated group compared to the control. Scientists found that 7CZ nanoparticles can infiltrate the damaged tissue and act locally at the infection site.

Treating sepsis has been an old challenge for physicians worldwide,” emphasizes LEE Seung-Hoon, professor of department of Neurology, Seoul National University Hospital. “This study shows the possibility of overcoming the limits of modern medicine with nanotechnology.”

This study has been published in the journal Angewandte Chemie.

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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.


Clothes Embedded With Nanoparticles Heal The Skin

Tiny capsules embedded in the clothes we wear could soon be used to counteract the rise of sensitive skin conditions.

As people are getting older, they have more sensitive skin, so there is a need to develop new products for skin treatment,” says Dr Carla Silva, from the Centre for Nanotechnology and Smart Materials (CENTI), in Portugal

This increased sensitivity can lead to painful bacterial infections such as dermatitis, otherwise known as eczema. Current treatments use silver-based or synthetic antibacterial elements, but these can create environmentally harmful waste and may have negative side effects.

To combat these bacterial infections in an eco-friendly way the EU-funded SKHINCAPS project is combining concentrated plant oil with nanotechnology. Their solution puts these so-called essential oils into tiny capsules that are hundreds of times smaller than the width of a human hair. Each one is programmed to release its payload only in the presence of the bacteria that cause the skin infections. This means that each capsule is in direct contact with the affected skin as soon as an infection occurs, increasing the effectiveness of the treatment.

According to Dr Silva, who is also project coordinator of SKHINCAPS, the nano-capsules are attached to the clothing material using covalent bonding, the strongest chemical bond found in nature. This ensures the capsules survive the washing machine and that they are invisible to whoever is wearing them. This nanotechnology has a lifespan equal to that of the garment, though the active ingredients contained in the nano-capsules will run out earlier depending on the extent of the skin infection, and thereby on how much of the treatment is released when the clothing is worn.

The nano-capsules will prove invaluable for chronic eczema sufferers and those with high levels of stress, as well as the elderly and diabetics, who are particularly vulnerable to developing such infections.


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.


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.


SuperPowerful Tiny Device Converts Light Into Electricity

In today’s increasingly powerful electronics, tiny materials are a must as manufacturers seek to increase performance without adding bulk. Smaller also is better for optoelectronic devices — like camera sensors or solar cells —which collect light and convert it to electrical energy. Think, for example, about reducing the size and weight of a series of solar panels, producing a higher-quality photo in low lighting conditions, or even transmitting data more quickly.

However, two major challenges have stood in the way: First, shrinking the size of conventionally used “amorphousthin-film materials also reduces their quality. And second, when ultrathin materials become too thin, they are almost transparent — and actually lose some ability to gather or absorb light.

Now, in a nanoscale photodetector that combines both a unique fabrication method and light-trapping structures, a team of engineers from the University at Buffalo (UB) and the University of Wisconsin-Madison (UW-Madison) has overcome both of those obstacles. The researchers — electrical engineers Qiaoqiang Gan at UB, and Zhenqiang (Jack) Ma and Zongfu Yu at UW-Madison — described their device, a single-crystalline germanium nanomembrane photodetector on a nanocavity substrate, in the July 7, 2017, issue of the journal Science Advances.

This image shows the different layers of the nanoscale photodetector, including germanium (red) in between layers of gold or aluminum (yellow) and aluminum oxide (purple). The bottom layer is a silver substrate

We’ve created an exceptionally small and extraordinarily powerful device that converts light into energy,” says Gan, associate professor of electrical engineering in UB’s School of Engineering and Applied Sciences, and one of the paper’s lead authors. “The potential applications are exciting because it could be used to produce everything from more efficient solar panels to more powerful optical fibers.”

The idea, basically, is you want to use a very thin material to realize the same function of devices in which you need to use a very thick material,” says Ma, the Lynn H. Matthias Professor and Vilas Distinguished Achievement Professor in electrical and computer engineering at UW-Madison, also a lead author. Nanocavities are made up of an orderly series of tiny, interconnected molecules that essentially reflect, or circulate, light.

The new device is an advancement of Gan’s work developing nanocavities that increase the amount of light that thin semiconducting materials like germanium can absorb. It consists of nanocavities sandwiched between a top layer of ultrathin single-crystal germanium and a bottom, reflecting layer of silver.


How To Strengthen 3-D Printed Parts

From aerospace and defense to digital dentistry and medical devices, 3-D printed parts are used in a variety of industries. Currently, 3-D printed parts are very fragile and traditionally used in the prototyping phase of materials or as a toy for display. A doctoral student in the Department of Materials Science and Engineering at Texas A&M University has pioneered a countermeasure to transform the landscape of 3-D printing today.

Brandon Sweeney and his advisor Dr. Micah Green, associate professor in the Department of Chemical Engineering, discovered a way to make 3-D printed parts stronger and immediately useful in real-world applications. Sweeney and Green applied the traditional welding concepts to bond the submillimeter layers in a 3-D printed part together, while in a microwave.

I was able to see the amazing potential of the technology, such as the way it sped up our manufacturing times and enabled our CAD designs to come to life in a matter of hours,” Sweeney said. “Unfortunately, we always knew those parts were not really strong enough to survive in a real-world application.

3-D printed objects are comprised of many thin layers of materials, plastics in this case, deposited on top of each other to form a desired shape. These layers are prone to fracturing, causing issues with the durability and reliability of the part when used in a real-world application, for example a custom printed medical device. “I knew that nearly the entire industry was facing this problem,” Sweeney said. “Currently, prototype parts can be 3-D printed to see if something will fit in a certain design, but they cannot actually be used for a purpose beyond that.”

When Sweeney started his doctorate, he was working with Green in the Department of Chemical Engineering at Texas Tech University. Green had been collaborating with Dr. Mohammad Saed, assistant professor in the electrical and computer engineering department at Texas Tech, on a project to detect carbon nanotubes using microwaves. The trio crafted an idea to use carbon nanotubes in 3-D printed parts, coupled with microwave energy to weld the layers of parts together.

The basic idea is that a 3-D part cannot simply be stuck into an oven to weld it together because it is plastic and will melt,” Sweeney said. “We realized that we needed to borrow from the concepts that are traditionally used for welding parts together where you’d use a point source of heat, like a torch or a TIG welder to join the interface of the parts together. You’re not melting the entire part, just putting the heat where you need it.” The technology is patent-pending and licensed with a local company, Essentium Materials.

The team recently published a paper “Welding of 3-D Printed Carbon Nanotube-Polymer Composites by Locally Induced Microwave Heating,” in Science Advances.


Hydrogen-based Electric Bus

FAST, a student team from Eindhoven University of Technology (TU/e) in Netherlands, has designed the world’s first system that allows a bus to drive on formic acid. Their self-built system comprises an electric bus that is hooked up to a small trailer – which the students have christened ‘REX’ – in which formic acid is converted into electricity. The benefits of using formic acid are that it is sustainable, CO2-neutral, safe and liquid.


Hydrozine is the energy carrier’s official name. It’s 99% formic acid with a performance enhancing agent. What is striking is that Team FAST, consisting of 35 students, developed this so far unknown fuel all by itself. At the beginning of 2016 they presented an initial scale model that illustrated how it works. After another twenty months of hard work, they now have a system that is 42,000 times stronger and is capable of 25kW power.

In the trailer that was built by the team hydrozine is split into hydrogen and CO2. The hydrogen is then used to produce electricity that powers a city bus of the Eindhoven company VDL. The team calls the trailer a ‘range extender’, REX for short, because the trailer expands the existing range of the bus as a standalone component. The team is still running final tests with the aim of the bus actually operating by the end of this year.

The benefits of hydrozine are many. It is a cheap and safe alternative to the transport of hydrogen that normally requires large tanks and high pressure. The CO2 produced in splitting the hydrozine is also used in the production process, which results in zero net CO2. Hydrozine has four times as much energy density as a battery and since it is a liquid, very few modifications will be required to the current infrastructure of filling stations.


How To Power The U.S. With Solar

Speaking recently at the National Governors Association Summer Meeting in Rhode Island, Elon Musk told his audience — including 30 United States governors — that it’s possible to power the nation with solar energy.

If you wanted to power the entire U.S. with solar panels, it would take a fairly small corner of Nevada or Texas or Utah; you only need about 100 miles by 100 miles of solar panels to power the entire United States,” Musk said. “The batteries you need to store the energy, to make sure you have 24/7 power, is 1 mile by 1 mile. One square-mile. That’s it.”

Why solar? Well, as Musk explained, as far as energy sources go, we can count on solar to come through for us: “People talk about fusion and all that, but the sun is a giant fusion reactor in the sky. It’s really reliable. It comes up every day. If it doesn’t we’ve got bigger problems.”

At present, about 10 percent of the U.S. is powered by renewable energy sources. To achieve a complete renewable energy power, Musk thinks solar is the way to go.

To start, he suggested combining rooftop solar and utility-scale solar plants. The former would be on the rooftops of houses in the suburbs, while the latter could power other areas. As we’ve seen with Tesla’s new rooftop solar unit, and efforts in other countries, like Australia, to build large-scale solar plants, this is a goal well within reach.

Next, while in transition from fossil fuel to solar, it’d be necessary to rely on other renewables. “We’ll need to be a combination of utility-scale solar and rooftop solar, combined with wind, geothermal, hydro, probably some nuclear for a while, in order to transition to a sustainable situation,” Musk explained.

Finally, the U.S. has to build more localized power sources, like the rooftop solar setups. “People do not like transmission lines going through their neighborhood, they really don’t like that, and I agree,” Musk said. “Rooftop solar, utility solar; that’s really going to be a solution from the physics standpoint. I can really see another way to really do it.”

When this happens, the U.S. would eliminate about 1,821 million metric tons of carbon dioxide (CO2) emissions generated by the country’s current electric power sector — 35 percent of the overall CO2 energy-related emissions in the U.S.


Solar Nanotechnology-based Desalination

A new desalination system has been developed that combines membrane distillation technology and light-harvesting nanophotonics. Called nanophotonics-enabled solar membrane distillation technology, or NESMD for short, the development has come from the Center for Nanotechnology Enabled Water Treatment (NEWT), based at Rice University. The system works whereby hot salt water is flowed across one side of a porous membrane and cold freshwater is flowed across the otherWater vapor is naturally drawn through the membrane from the hot to the cold side, and because the seawater doesn’t need to be boiled, the energy requirements are less than they would be for traditional distillation, according to the researchers. However, the energy costs are still significant because heat is continuously lost from the hot side of the membrane to the cold.

Unlike traditional membrane distillation, NESMD benefits from increasing efficiency with scale,” said Rice’s Naomi Halas, a corresponding author on the paper and the leader of NEWT‘s  nanophotonics research efforts. “It requires minimal pumping energy for optimal distillate conversion, and there are a number of ways we can further optimise the technology to make it more productive and efficient.

The distillation membrane in the chamber contained a specially designed top layer of carbon black nanoparticles infused into a porous polymer. The light-capturing nanoparticles heated the entire surface of the membrane when exposed to sunlight. A thin half-millimeter-thick layer of salt water flowed atop the carbon-black layer, and a cool freshwater stream flowed below.

Rice scientist and water treatment expert Qilin Li said the water production rate increased greatly by concentrating the sunlight: “The intensity got up 17.5 kilowatts per meter squared when a lens was used to concentrate sunlight by 25 times, and the water production increased to about 6 liters per meter squared per hour.”

In the PNAS study, researchers offered proof-of-concept results based on tests with an NESMD chamber about the size of three postage stamps and just a few millimeters thick.


Sion, The Solar-Powered Car

What has room for 6 passengers, an all-electric range of up to 155 miles (250 kilometers), and a body covered in solar panels that can add as many as 18 miles (30 kilometers) of driving a day from sunlight? That would be the Sono Motors Sion, an innovative solar-powered car from a team of German entrepreneurs that is scheduled to have its world debut on July 27 (2017).

The Sion project was able to move forward thanks to an Indiegogo crowdfunding campaign last year that raised over a half million dollars. More than 1,000 people have participated so far.

The car will have two versions. The Urban comes with a 14.4 kilowatt-hour battery pack. It has a range of about 75 miles (121 kilometers) and will cost $13,200. The Extender version has a 30 kilowatt-hour battery and a range of 155 miles (250 kilometers). Its target price is $17,600. Neither price includes the battery. Like the Renault Zoe, customers will either buy the battery separately or lease it. The leasing option gives owners the flexibility to upgrade the battery later as improvements in battery technology become available.

The hood, roof, and rear hatch of the Sion are covered with monocrystalline silicon cells that are 21% efficient. On a sunny day, they can generate enough electricity to add 18 miles of range. The solar cells are 8 millimeters thick and embedded in a polycarbonate layer that is shatterproof, weather resistant, and light in weight. The Sion can also be 80% charged using an AC outlet in about 30 minutes, according to company claims. No DC charging option is available. The car also comes with an outlet that can power electronic devices.

Inside, all the seats of the 5 door hatchback fold flat, offering multiple configurations for carrying passengers and cargo. There is a 10 inch center display and smartphone connectivity via WiFi or Bluetooth. The ventilation system is called breSono and incorporates a dollop of moss, which is said to act as a natural filter when an electrical charge is applied.

The company will offer an online maintenance and repair system it calls reSono. It allows owners to order parts online and comes with a video that shows them how to install the parts when they arrive.  Or they can take the car and the parts to any local auto repair shop facility to get them installed.


Cancer: A Giant Step For Immunotherapy

A Food and Drug Administration (FDA) panel opened a new era in medicine, unanimously recommending that the agency approve the first-ever treatment that genetically alters a patient’s own cells to fight cancer, transforming them into what scientists call “a living drug” that powerfully bolsters the immune system to shut down the disease.

If the F.D.A. accepts the recommendation, which is likely, the treatment will be the first gene therapy ever to reach the market. Others are expected: Researchers and drug companies have been engaged in intense competition for decades to reach this milestone. Novartis is now poised to be the first. Its treatment is for a type of leukemia, and it is working on similar types of treatments in hundreds of patients for another form of the disease, as well as multiple myeloma and an aggressive brain tumor.

To use the technique, a separate treatment must be created for each patient — their cells removed at an approved medical center, frozen, shipped to a Novartis plant for thawing and processing, frozen again and shipped back to the treatment center.

A single dose of the resulting product has brought long remissions, and possibly cures, to scores of patients in studies who were facing death because every other treatment had failed. The panel recommended approving the treatment for B-cell acute lymphoblastic leukemia that has resisted treatment, or relapsed, in children and young adults aged 3 to 25.


We believe that when this treatment is approved it will save thousands of children’s lives around the world,” Emily’s father, Tom Whitehead, told the panel. “I hope that someday all of you on the advisory committee can tell your families for generations that you were part of the process that ended the use of toxic treatments like chemotherapy and radiation as standard treatment, and turned blood cancers into a treatable disease that even after relapse most people survive.”

The main evidence that Novartis presented to the F.D.A. came from a study of 63 patients who received the treatment from April 2015 to August 2016. Fifty-two of them, or 82.5 percent, went into remission — a high rate for such a severe disease. Eleven others died.

It’s a new world, an exciting therapy,” said Dr. Gwen Nichols, the chief medical officer of the Leukemia and Lymphoma Society, which paid for some of the research that led to the treatment. The next step, she said, will be to determine “what we can combine it with and is there a way to use it in the future to treat patients with less disease, so that the immune system is in better shape and really able to fight.” She added, “This is the beginning of something big.”