Posts belonging to Category Materials



Super-Efficient Production Of Hydrogen From Solar Energy

Hydrogen is an alternative source of energy that can be produced from renewable sources of sunlight and water. A group of Japanese researchers has developed a photocatalyst that increases hydrogen production tenfold.

When light is applied to photocatalysts, electrons and holes are produced on the surface of the catalyst, and hydrogen is obtained when these electrons reduce the hydrogen ions in water. However, in traditional photocatalysts the holes that are produced at the same time as the electrons mostly recombine on the surface of the catalyst and disappear, making it difficult to increase conversion efficiency.

Professor Tachikawa’s research group from the Kobe University developed a photocatalyst made of mesocrystal, deliberately creating a lack of uniformity in size and arrangement of the crystals. This new photocatalyst is able to spatially separate the electrons and electron holes to prevent them recombining. As a result, it has a far more efficient conversion rate for producing hydrogen than conventional nanoparticulate photocatalysts (approximately 7%).

The team developed a new method called “Topotactic Epitaxial Growth” that uses the nanometer-sized spaces in mesocrystals.
Using these findings, the research group plans to apply mesocrystal technology to realizing the super-efficient production of hydrogen from solar energy. The perovskite metal oxides, including strontium titanate, the target of this study, are the fundamental materials of electronic elements, so their results could be applied to a wide range of fields.

The discovery was made by a joint research team led by Associate Professor Tachikawa Takashi (Molecular Photoscience Research Center, Kobe University) and Professor Majima Tetsuro (Institute of Scientific and Industrial Research, Osaka University). Their findings were published  in the online version of Angewandte Chemie International Edition.

Source: http://www.kobe-u.ac.jp/

Asthma: Graphene-Based Sensor Improves Treatment

Scientists from Rutgers University have created a graphene-based sensor that could lead to earlier detection of looming asthma attacks and improve the management of asthma and other respiratory diseases, preventing hospitalizations and deaths.

The sensor paves the way for the development of devices – possibly resembling fitness trackers like the Fitbit – which people could wear and then know when and at what dosage to take their medication.


Exhaled breath condensate (tiny droplets of liquid) are rapidly analyzed by a graphene-based nanoelectronic sensor that detects nitrite, a key inflammatory marker in the inner lining of the respiratory airway.

Our vision is to develop a device that someone with asthma or another respiratory disease can wear around their neck or on their wrist and blow into it periodically to predict the onset of an asthma attack or other problems,” said Mehdi Javanmard, an assistant professor in the Department of Electrical and Computer Engineering. “It advances the field of personalized and precision medicine.

Javanmard and a diverse team of RutgersNew Brunswick experts describe their invention in a study published online today in the journal Microsystems & Nanoengineering.

Asthma, which causes inflammation of the airway and obstructs air flow, affects about 300 million people worldwide. About 17.7 million adults and 6.3 million children in the United States were diagnosed with asthma in 2014. Symptoms include coughing, wheezing, shortness of breath, and chest tightness. Other serious lung ailments include chronic obstructive pulmonary disease (COPD), which encompasses emphysema and chronic bronchitis.

Measuring biomarkers in exhaled breath condensatetiny liquid droplets discharged during breathing – can contribute to understanding asthma at the molecular level and lead to targeted treatment and better disease management. The Rutgers researchers’ miniaturized electrochemical sensor accurately measures nitrite in exhaled breath condensate using reduced graphene oxide. Reduced graphene oxide resists corrosion, has superior electrical properties and is very accurate in detecting biomarkers.

Source: http://news.rutgers.edu/

Self-Healing Lithium-Ion Batteries

Researchers at the University of Illinois have found a way to apply self-healing technology to lithium-ion batteries to make them more reliable and last longer.

The group developed a battery that uses a silicon nanoparticle composite material on the negatively charged side of the battery and a novel way to hold the composite together – a known problem with batteries that contain silicon.

Materials science and engineering professor Nancy Sottos and aerospace engineering professor Scott White led the study published in the journal Advanced Energy Materials.

“This work is particularly new to self-healing materials research because it is applied to materials that store energy,” White said. “It’s a different type of objective altogether. Instead of recovering structural performance, we’re healing the ability to store energy.”

The negatively charged electrode, or anode, inside the lithium-ion batteries that power our portable devices and electric cars are typically made of a graphite particle composite. These batteries work well, but it takes a long time for them to power up, and over time, the charge does not last as long as it did when the batteries were new.

Silicon has such a high capacity, and with that high capacity, you get more energy out of your battery, except it also undergoes a huge volume expansion as it cycles and self-pulverizes,” Sottos explained.

Past research found that battery anodes made from nanosized silicon particles are less likely to break down, but suffer from other problems.

You go through the charge-discharge cycle once, twice, three times, and eventually you lose capacity because the silicon particles start to break away from the binder,” White said.

To combat this problem, the group further refined the silicon anode by giving it the ability to fix itself on the fly. This self-healing happens through a reversible chemical bond at the interface between the silicon nanoparticles and polymer binder.

Source: https://news.illinois.edu/

The Rise Of The Cyborg

Researchers from UCLA and the University of Connecticut have designed a new biofriendly energy storage system called a biological supercapacitor, which operates using charged particles, or ions, from fluids in the human body. The device is harmless to the body’s biological systems, and it could lead to longer-lasting cardiac pacemakers and other implantable medical devices like artificial heart.

The UCLA team was led by Richard Kaner, a distinguished professor of chemistry and biochemistry, and of materials science and engineering, and the Connecticut researchers were led by James Rusling, a professor of chemistry and cell biology. A paper about their design was published this week in the journal Advanced Energy Materials.

Pacemakers — which help regulate abnormal heart rhythms — and other implantable devices have saved countless lives. But they’re powered by traditional batteries that eventually run out of power and must be replaced, meaning another painful surgery and the accompanying risk of infection. In addition, batteries contain toxic materials that could endanger the patient if they leak.

The researchers propose storing energy in those devices without a battery. The supercapacitor they invented charges using electrolytes from biological fluids like blood serum and urine, and it would work with another device called an energy harvester, which converts heat and motion from the human body into electricity — in much the same way that self-winding watches are powered by the wearer’s body movements. That electricity is then captured by the supercapacitor.

Combining energy harvesters with supercapacitors can provide endless power for lifelong implantable devices that may never need to be replaced,” said Maher El-Kady, a UCLA postdoctoral researcher and a co-author of the study.

Source: http://newsroom.ucla.edu/

Super-material Bends, Shapes And Focuses Sound Waves

These tiny 3D-printed bricks could one day allow people to create their own acoustics. That’s the plan of scientists from the universities of Bristol and Sussex. They’ve invented a metamaterial which bends and manipulates sound in any way the user wants. It’s helped scientists create what they call a ‘sonic alphabet‘.

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We have discovered that you just need 16 bricks to make any type of sound that you can imagine. You can shape the sound just with 16 of them, just like you create any words with just 26 letters,” says Dr. Gianluca Memoli, researcher at Interact Lab at University of Sussex.

DIY kits like this, full of batches of the 16 aural letters, could help users create a sound library, or even help people in the same car to hear separate things.

With our device what you can have is you can strap a static piece on top of existing speakers and they can direct sound in two different directions without any overlap. So the passengers can hear completely different information from the driver,” explains Professor Sri Subramanian Interact Lab at University of Sussex. This technology is more than five years away, but smaller versions could be used to direct medical ultrasound devices far sooner.  “In a year we could have a sleeve that we can put on top of already existing projects in the market and make them just a little bit better. For example, we can have a sleeve that goes on top of ultrasound pain relieving devices that are used for therapeutic pain,” he adds.
Researchers say spatial sound modulators will one day allow us to perform audible tasks previously unheard of.

Source: http://www.sussex.ac.uk/

Stephen Hawking Warns: Only 100 Years Left For Humankind Before Extinction

It’s no secret that physicist Stephen Hawking thinks humans are running out of time on planet Earth.

In a new BBC documentary, Hawking will test his theory that humankind must colonize another planet or perish in the next 100 years. The documentary Stephen Hawking: Expedition New Earth, will air this summer as part of BBC’s Tomorrow’s World season and will showcase that Hawking‘s aspiration “isn’t as fantastical as it sounds,” according to BBC.

For years, Hawking has warned that humankind faces a slew of threats ranging from climate change to destruction from nuclear war and genetically engineered viruses.

While things look bleak, there is some hope, according to Hawking. Humans must set their sights on another planet or perish on Earth.

We must also continue to go into space for the future of humanity,” Hawking said during a 2016 speech at Britain’s Oxford University Union. In the past, Hawking has suggested that humankind might not survive another 1000 years without escaping beyond our fragile planet.” The BBC documentary hints at an adjusted timeframe for colonization, which many may see in their lifetime.

3D Printing Art And Design in Paris

Do you plan  to travel to Paris? In this case do not miss to visit the Centre Pompidou,  this huge museum, located in the center of Paris and dedicated to modern Art.  You can assist to  “Mutations/Créations“: a new event decidedly turned towards the future and the interaction between digital technology and creation; a territory shared by art, innovation and science.

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Drawing on all the disciplines in a mix of research, art and engineering, the first edition of this annual event calls upon music, design and architecture. It consists of two exhibitions (“Imprimer le monde“ and “Ross Lovegrove“), an Art/Innovation Forum entitled “Vertigo“, and various study days and get-togethers. Each year, thematic and monographic exhibitions will be staged around meetings and workshops that turn the Centre Pompidou into an “incubator“: a place for demonstrating prototypes, carrying out artistic experiments in vivo, and talking with designers. This platform will also be a critical observatory and a tool for analysing the impact of creation on society. How have the various forms of creation begun using digital technologies to open up new industrial perspectives? How do they question the social, economic and political effects of these industrial developments, and their ethical limits? What formal transformations have come about in music, art, design and architecture with regard to technical and scientific progress?


In the same space,  you can see a  new retrospective devoted to British designer Ross Lovegrove, which shows how the artist has introduced a fresh dialogue between nature and technology, where art and science converge. He employs a “holistic“ idea of design through a visionary practice that began incorporating digital changes during the 1990s, rejecting the productivism of mass industry and replacing it with a more economical approach to materials and forms. This exhibition emphasises the role of design in the postindustrial era, now that we are seeing a significant shift from mechanics to organics: a changeover symptomatic of our times, which these “digital forms“ endeavour to highlight.

Source: https://www.centrepompidou.fr/

College Student 3D Prints His Own Braces

Amos Dudley wears his skills in his smile. The digital design major has been straightening his top teeth for the past 16 weeks using clear braces he made himself.

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 “I’m still wearing the last one,” said Dudley . “The last one” refers to the twelfth and final straightening tray in his self-designed treatment. Dudley said he had braces when he was in junior high, but he didn’t wear his retainer as much as he should have, and his teeth shifted. Over time, Dudley discovered that he wasn’t smiling as much because he wasn’t happy with the way his teeth looked.

Name brand options for clear braces can cost up to $8,000, according to companies like Invisalign, Damon, and ClearCorrect. But the 24-year-old wanted to save money, so he found a way to manufacture his own for less than $60. The total cost is so low because he only had to pay for materials used to make the models of his teeth and the retainers. Even though he built his own 3D printer at home, he opted to use a high-end and more precise 3D printer at his school, New Jersey Institute of Technology.

He used NJIT’s equipment to scan and print models of his teeth, and mold non-toxic plastic around them to form the set of 12 clear braces. Dudley determined out how far he needed to move his teeth to correct the misalignment problems. Then divided it by the maximum recommended distance a tooth should travel to determine the design for each alignment tray. Orthodontists use a similar process. Researching the materials he needed and figuring out how teeth move was the most difficult part of Dudley’s orthodontic adventure. The most exciting was when he finally put the first aligner in his mouth. “It was very obvious which tooth [the tray] was putting pressure on,” he said. “I was sort of worried about accumulated error, but that wasn’t the case so that was a pretty glorious moment.

Source: http://money.cnn.com/

Wood Mixed With Nanoparticles Filters Toxic Water

Engineers at the University of Maryland have developed a new use for wood: to filter water. Liangbing Hu of the Energy Research Center and his colleagues added nanoparticles to wood, then used it to filter toxic dyes from water.

The team started with a block of linden wood, which they then soaked in palladium – a metal used in cars’ catalytic converters to remove pollutants from the exhaust. In this new filter, the palladium bonds to particles of dye. The wood’s natural channels, that once moved water and nutrients between the leaves and roots, now allow the water to flow past the nanoparticles for efficient removal of the toxic dye particles. The water, tinted with methylene blue, slowly drips through the wood and comes out clear.

VIDEO: Wood filter removes toxic dye from water

This could be used in areas where wastewater contains toxic dye particles,” said Amy Gong, a materials science graduate student, and co-first author of the research paper.

The purpose of the study was to analyze wood via an engineering lens. The researchers did not compare the filter to other types of filters; rather, they wanted to prove that wood can be used to remove impurities.

We are currently working on using a wood filter to remove heavy metals, such as lead and copper, from water,’ said Liangbing Hu, the lead researcher on the project. “We are also interested in scaling up the technology for real industry applications.” Hu is a professor of materials science and a member of the University of Maryland’s Energy Research Center.

Source: http://www.mse.umd.edu/

Dissolvable Metal Supports for 3D Printing

Support for a visiting professor plus an off-the-cuff remark have led an Arizona State University (ASU) researcher to develop what could be the Holy Grail solution to speeding up the end-to-end process of metal 3D printing.

Owen Hildreth, ASU assistant professor of 3D Nanofabrication, was developing new approaches to reactive silver ink production when he thought he’d sit in on talks regarding the soon-to-be-opened ASU Polytechnic Manufacturing Research and Innovation Hub. One of the speakers, Timothy Simpson, was describing the practical challenges of setting up an additive manufacturing (AM) lab.

Combining a mechanical engineering degree (applied to five years’ work in the 2D printing industry) with a Ph.D. in nanofabrication materials engineering, Hildreth just may have been in the perfect position to bring a fresh perspective to the metal support problem. In contrast to the use of mechanical tools such as wire-EDM equipment, his concept would cause certain areas of a metal AM part to react chemically when immersed in a corrosive solution. The goal was to produce controlled degradation that would literally eat away the supports but leave the actual part virtually intact.

However, because multi-material 3D printing systems are not yet widely available, Hildreth also investigated ways to selectively remove the supports of powder-bed-type metal AM parts. Starting with a simple design for demonstration — a small 17-4 stainless steel cylinder 3D-printed with a single row of 100-micron-diameter needle-like supports — he tested two possible approaches.

In the first one, termed direct dissolution, the part was heat-treated (annealed) while packed with sodium ferrocyanide; this step precipitated out much of the protective chromium carbide, rendering the no-longer-stainless steel susceptible to chemical etching. The latter process was successful, but the part itself experienced significant etching, which continued the longer the part was allowed to sit in the solution.

Source: http://www.rapidreadytech.com/

Nuclear Energy: Fusion Power A Step Closer

The UK’s newest fusion reactor, ST40, was switched on last week, and has already managed to achieve ‘first plasma‘ – successfully generating a scorching blob of electrically-charged gas (or plasma) within its core.

The aim is for the tokamak reactor to heat plasma up to 100 million degrees Celsius (180 million degrees Fahrenheit) by 2018 – seven times hotter than the centre of the Sun. That’s the ‘fusion’ threshold, at which hydrogen atoms can begin to fuse into helium, unleashing limitless, clean energy in the process.

Nuclear fusion is the process that fuels our Sun, and if we can figure out a way to achieve the same thing here on Earth, it would allow us to tap into an unlimited supply of clean energy that produces next to no carbon emissions.Unlike nuclear fission, which is achieved in today’s nuclear reactors, nuclear fusion involves fusing atoms together, not splitting them apart, and it requires little more than salt and water, and primarily produces helium as a waste product.

 

Today is an important day for fusion energy development in the UK, and the world,” said David Kingham, CEO of Tokamak Energy, the company behind ST40. “We are unveiling the first world-class controlled fusion device to have been designed, built and operated by a private venture. The ST40 is a machine that will show fusion temperatures – 100 million degrees – are possible in compact, cost-effective reactors. This will allow fusion power to be achieved in years, not decades.

The next step is for a full set of those magnetic coils to be installed and tested within ST40, and later this year, Tokamak Energy will use them to aim to generate plasma at temperatures of 15 million degrees Celsius (27 million degrees Fahrenheit).

In 2018, the team hopes to achieve the fusion threshold of 100 million degrees Celsius (180 million degrees Fahrenheit), and the ultimate goal is to provide clean fusion power to the UK grid by 2030.

Source: http://www.tokamakenergy.co.uk/

Nanostructured High-Strength LightWeight Concrete

Scientists from the Peter the Great Saint-Petersburg Polytechnic University (SPbPU) in Russia, have created several types of building blocks based on nanostructured high-strength lightweight concrete, reinforced with skew-angular composite coarse grids. The development has unique characteristics, enabling the increase of load-carrying capability by more than 200% and decrease in specific density of the construction by 80%. In addition, among the advantages, are resistance to corrosion, aggressive environments and excessive frost resistance.

Researchers calculated that the service life of the building structures, made with the use of this reinforcement system, will increase at least 2-3 times in comparison with its modern analogs.

Such system allows to ensure the structure integrity even in conditions of seismic activity, since the load is distributed throughout the structure as a whole, and not by individual reinforcement bars. The invention can be used in the construction of bridges and pedestrian crossings, non-metallic ships, low-rise residential buildings” says Alexander Rassokhin, graduate student at SPbPU. Andrey Ponomarev, Professor of the Institute of Civil Engineering is the co-inventor of the new  construction technology.

The fundamentals of the research have been described in an article “Hybrid wood-polymer composites in civil engineering” at the Magazine of Civil Engineering.

Source: https://www.eurekalert.org/