Articles from June 2015



Electric Car: Nanogenerator Harvests Power From Rolling Tires

A group of University of Wisconsin-Madison engineers and a collaborator from China have developed a nanogenerator that harvests energy from a car’s rolling tire friction.

An innovative method of reusing energy, the nanogenerator ultimately could provide automobile manufacturers a new way to squeeze greater efficiency out of their vehicles. Xudong Wang, the Harvey D. Spangler fellow and an associate professor of materials science and engineering at UW-Madison, and his PhD student Yanchao Mao have been working on this device for about a year.

The nanogenerator relies on the triboelectric effect to harness energy from the changing electric potential between the pavement and a vehicle’s wheels. The triboelectric effect is the electric charge that results from the contact or rubbing together of two dissimilar objects.

Wang says the nanogenerator provides an excellent way to take advantage of energy that is usually lost due to friction.

Tesla-Model-S

The friction between the tire and the ground consumes about 10 percent of a vehicle’s fuel,” he says. “That energy is wasted. So if we can convert that energy, it could give us very good improvement in fuel efficiency.”

The researchers reported their development, which is the first of its kind, in a paper published May 6, 2015, in the journal Nano Energy.

Source: http://www.news.wisc.edu/

Full-Color, Flexible, Skin-like Display

Imagine a soldier who can change the color and pattern of his camouflage uniform from woodland green to desert tan at will. Or an office worker who could do the same with his necktie. Is someone at the wedding reception wearing the same dress as you? No problem – switch yours to a different color in the blink of an eye.

A breakthrough in a University of Central Florida (UCF) lab has brought those scenarios closer to reality. A team led by Professor Debashis Chanda of UCF’s NanoScience Technology Center and the College of Optics and Photonics (CREOL) has developed a technique for creating the world’s first full-color, flexible thin-film reflective display.

Chanda’s research was inspired by nature. Traditional displays like those FLEXIon a mobile phone require a light source, filters and a glass plates. But animals like chameleons, octopuses and squids are born with thin, flexible, color-changing displays that don’t need a light source – their skin.

Switch-color-world-first-full-color-flexible-skin-like-display

All manmade displays – LCD, LED, CRT – are rigid, brittle and bulky. But you look at an octopus, they can create color on the skin itself covering a complex body contour, and it’s stretchable and flexible,” Chanda said. “That was the motivation: Can we take some inspiration from biology and create a skin-like display?”

As detailed in the cover article of the June issue of the journal Nature Communications, Chanda is able to change the color on an ultrathin nanostructured surface by applying voltage. The new method doesn’t need its own light source. Rather, it reflects the ambient light around it.

Source: http://today.ucf.edu/

Nanorobots Swim Through Blood To Deliver Drugs

Someday, treating patients with nanorobots could become standard practice to deliver medicine specifically to parts of the body affected by disease. But merely injecting drug-loaded nanoparticles might not always be enough to get them where they need to go. Now scientists are reporting in the ACS journal Nano Letters the development of new nanoswimmers that can move easily through body fluids to their targets.
nanorobots to deliver drugsCLICK ON THE IMAGE TO ENJOY THE VIDEO

Tiny robots could have many benefits for patients. For example, they could be programmed to specifically wipe out cancer cells, which would lower the risk of complications, reduce the need for invasive surgery and lead to faster recoveries. It’s a burgeoning field of study with early-stage models currently in development in laboratories. But one of the challenges to making these robots work well is getting them to move through body fluids, which are like molasses to something as small as a nanorobot. Bradley J. Nelson, Salvador Pané, from ETH Zürich (Switzerland), Yizhar Or from Technion (Israel)  and colleagues wanted to address this problem. The researchers strung together three links in a chain about as long as a silk fiber is wide. One segment was a polymer, and two were magnetic, metallic nanowires. They put the tiny devices in a fluid even thicker than blood. And when they applied an oscillating magnetic field, the nanoswimmer moved in an S-like, undulatory motion at the speed of nearly one body length per second. The magnetic field also can direct the swimmers to reach targets.

Source; http://pubs.acs.org/

How To Store Solar Energy Up To Several Weeks

The materials in most of today’s residential rooftop solar panels can store energy from the sun for only a few microseconds at a time. A new technology developed by chemists at UCLA is capable of storing solar energy for up to several weeks — an advance that could change the way scientists think about designing solar cells.

The new design is inspired by the way that plants generate energy through photosynthesis.
bundle of polymers

The scientists devised a new arrangement of solar cell ingredients, with bundles of polymer donors (green rods) and neatly organized fullerene acceptors (purple, tan).
Biology does a very good job of creating energy from sunlight,” said Sarah Tolbert, a UCLA professor of chemistry and one of the senior authors of the research. “Plants do this through photosynthesis with extremely high efficiency.” “In photosynthesis, plants that are exposed to sunlight use carefully organized nanoscale structures within their cells to rapidly separate charges — pulling electrons away from the positively charged molecule that is left behind, and keeping positive and negative charges separated,” Tolbert said. “That separation is the key to making the process so efficient.

To capture energy from sunlight, conventional rooftop solar cells use silicon, a fairly expensive material.  There is currently a big push to make lower-cost solar cells using plastics, rather than silicon, but today’s plastic solar cells are relatively inefficient, in large part because the separated positive and negative electric charges often recombine before they can become electrical energy.

Modern plastic solar cells don’t have well-defined structures like plants do because we never knew how to make them before,” Tolbert said. “But this new system pulls charges apart and keeps them separated for days, or even weeks. Once you make the right structure, you can vastly improve the retention of energy.”

The findings are published June 19 in the journal Science.

 

Source: http://newsroom.ucla.edu/

Therapy Stops Atherosclerosis

In what may be a major leap forward in the quest for new treatments of the most common form of cardiovascular disease, scientists at Johns Hopkins report they have found a way to halt and reverse the progression of atherosclerosis in rodents by loading microscopic nanoparticles with a chemical that restores the animals’ ability to properly handle cholesterol.


cholesterol2Cholesterol
is a fatty substance that clogs, stiffens and narrows the blood vessels, greatly diminishing their ability to deliver blood to the heart muscle and the brain. The condition, known as atherosclerotic vessel disease, is the leading cause of heart attacks and strokes that claim some 2.6 million lives a year worldwide, according to the World Health Organization.

A report on the work, published online in the journal Biomaterials, builds on recent research by the same team that previously identified a fat-and-sugar molecule called GSL as the chief culprit behind a range of biological glitches that affect the body’s ability to properly use, transport and purge itself of vessel-clogging cholesterol.

That earlier study showed that animals feasting on high-fat foods remained free of heart disease if pretreated with a man-made compound, D-PDMP, which works by blocking the synthesis of the mischievous GSL. But the body‘s natural tendency to rapidly break down and clear out D-PDMP was a major hurdle in efforts to test its therapeutic potential in larger animals and humans. The newly published report reveals the scientists  have cleared that hurdle by encapsulating D-PDMP into tiny molecules, which are absorbed faster and linger in the body much longer. In this case, the researchers say, their experiments show that when encapsulated that way, D-PDMP’s potency rose ten-fold in animals fed with it. Most strikingly, the team reports, the nano version of the compound was potent enough to halt the progression of atherosclerosis. As well, the nano-packaged drug improved physiologic outcomes among animals with heart muscle thickening and pumping dysfunction, the hallmarks of advanced disease.

Our experiments illustrate clearly that while content is important, packaging can make or break a drug,” says lead investigator Subroto Chatterjee, Ph.D., a professor of medicine and pediatrics at the Johns Hopkins University School of Medicine and a metabolism expert at its Heart and Vascular Institute.In our study, the right packaging vastly improved the drug’s performance and its ability not merely to prevent disease but to mitigate some of its worst manifestations.”

Source: http://www.eurekalert.org/

Wood Added With Carbon Nanotubes Printed In 3D

Paul Gatenholm, professor in Polymer TA group of researchers at Chalmers University of Technology (Sweden)  have managed to print and dry three-dimensional objects made entirely by cellulose for the first time with the help of a 3D-bioprinter. They also added carbon nanotubes to create electrically conductive material. The effect is that cellulose and other raw material based on wood will be able to compete with fossil-based plastics and metals in the on-going additive manufacturing revolution, which started with the introduction of the 3D-printer.

3D printing is a form of additive manufacturing that is predicted to revolutionise the manufacturing industry. The precision of the technology makes it possible to manufacture a whole new range of objects and it presents several advantages compared to older production techniques. The freedom of design is great, the lead time is short, and no material goes to wastePlastics and metals dominate additive manufacturing. However, a research group at Chalmers University of Technology have now managed to use cellulose from wood in a 3D printer.

wood computer chipCombing the use of cellulose to the fast technological development of 3D printing offers great environmental advantages,” says Paul Gatenholm, professor of Biopolymer Technology at Chalmers and the leader of the research group. “Cellulose is an unlimited renewable commodity that is completely biodegradable, and manufacture using raw material from wood, in essence, means to bind carbon dioxide that would otherwise end up in the atmosphere.”

The breakthrough was accomplished at Wallenberg Wood Science Center, a research center aimed at developing new materials from wood, at Chalmers University of Technology.

 

Source: http://www.chalmers.se/

Graphene Boosts By 30 Percent Chips Speeds

A typical computer chip includes millions of transistors connected with an extensive network of copper wires. Although chip wires are unimaginably short and thin compared with household wires, both have one thing in common: in each case the copper is wrapped within a protective sheath. For years a material called tantalum nitride has formed a protective layer around chip wires.

Now Stanford-led experiments demonstrate that a different sheathing material, graphene, can help electrons scoot through tiny copper wires in chips more quickly.

Graphene is a single layer of carbon atoms arranged in a strong yet thin lattice. Stanford electrical engineer H.-S. Philip Wong says this modest fix, using graphene to wrap wires, could allow transistors to exchange data faster than is currently possible.  And the advantages of using graphene could become greater in the future as transistors continue to shrink.

graphene Stanford

“Researchers have made tremendous advances on all of the other components in chips, but recently there hasn’t been much progress on improving the performance of the wires,” he said.

Wong, the Willard R. and Inez Kerr Bell Professor in the School of Engineering, led a team of six researchers, including two from the University of Wisconsin-Madison, who will present their findings at the Symposia of VLSI Technology and Circuits in Kyoto, Japan, a leading venue for the electronics industry. Ling Li, a graduate student in electrical engineering at Stanford and first author of the research paper, will explain why changing the exterior wrapper on connecting wires can have such a big impact on chip performance.

Source: http://engineering.stanford.edu/

How to Make Carbon Nanoparticles In Your Kitchen

Researchers led by University of Illinois bioengineering professors Dipanjan Pan and Rohit Bhargava, have found an easy way to produce carbon nanoparticles that are small enough to evade the body’s immune system, reflect light in the near-infrared range for easy detection, and carry payloads of pharmaceutical drugs to targeted tissues. Unlike other methods of making carbon nanoparticles – which require expensive equipment and purification processes that can take days – the new approach generates the particles in a few hours and uses only a handful of ingredients, including store-bought molasses.


nanoparticles-300x225

If you have a microwave and honey or molasses, you can pretty much make these particles at home,” Pan said. “You just mix them together and cook it for a few minutes, and you get something that looks like char, but that is nanoparticles with high luminescence. This is one of the simplest systems that we can think of. It is safe and highly scalable for eventual clinical use.

These “next-generation” carbon spheres have several attractive properties, the researchers found. They naturally scatter light in a manner that makes them easy to differentiate from human tissues, eliminating the need for added dyes or fluorescing molecules to help detect them in the body.

The nanoparticles are coated with polymers that fine-tune their optical properties and their rate of degradation in the body. The polymers can be loaded with drugs that are gradually released.
The nanoparticles also can be made quite small, less than eight nanometers in diameter (a human hair is 80,000 to 100,000 nanometers thick).

Our immune system fails to recognize anything under 10 nanometers,” Pan said. “So, these tiny particles are kind of camouflaged, I would say; they are hiding from the human immune system.

The researchers report their findings in the journal Small.

Source: http://news.illinois.edu/

3D-Printed Steel Bridge In Amsterdam

From low-cost housing to life-saving implants, 3D printing technology is having a growing influence on our lives, and the latest innovation to be announced is a full-sized 3D-printed bridge.

Industry experts MX3D are planning to create a steel bridge in Amsterdam in the Netherlands using independent robot arms. These arms will start on one side of the river and cross over to the other bank, building the structure as they go.

Software studio Autodesk and construction firm Heijmans are two of the partners working with MX3D on the eye-catching project, which is scheduled to start in September once a final location has been chosen. The robotic 3D printers are going to construct their own supports as they go, heating the metal to 1,500 degrees Celsius (2,732 Fahrenheit) before melding it into place.

The site is set to be a tourist attraction even before it’s completed, with a visitor centre in the pipeline that will provide running updates on the bridge’s process.

3D-Printed-Steel-Bridge-Amsterdam-What distinguishes our technology from traditional 3D printing methods is that we work according to the ‘printing outside the box’ principle,” MX3D Chief Technology Officer Tim Geurtjens says on the project site.

By printing with 6-axis industrial robots, we are no longer limited to a square box in which everything happens. Printing a functional, life-size bridge is of course the ideal way to showcase the endless possibilities of this technique.”

The printing arms have been through several iterations to get them ready for the task: MX3D engineers say they’ve seen machines explode, get clogged up and lose their bearings along the way, but now the final version of the hardware is ready to launch into action. A small-scale test run has already taken place, producing a bridge a few feet across that could take the weight of a human being.

The style of the bridge has been sketched out by Dutch designer and artist Joris Laarman. “I strongly believe in the future of digital production and local production, in ‘the new craft’,” he says. “This bridge will show how 3D printing finally enters the world of large-scale, functional objects and sustainable materials while allowing unprecedented freedom of form. The symbolism of the bridge is a beautiful metaphor to connect the technology of the future with the old city, in a way that brings out the best of both worlds.

Source: http://mx3d.com/
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http://www.sciencealert.com/

Hydrogen Batteries Power Airliners Galley

Fuel cells hidden inside trolleys used to serve passengers their in-flight drinks could generate enough additional energy to power an airliner’s entire galley, according to German researchers. Passengers on airliners are used to their in-flight snacks coming from the flight attendant’s trolley. In the future, that trolley could provide enough power to cook a plane-load of meals. German researchers have been showcasing their portable fuel cell at the Paris Air show.

air attendantCLICK ON THE IMAGE TO ENJOY THE VIDEO

What you see here is an energy generation system with a tank, a reformer, a fuel cell and a battery. The fuel cell hybrid system produces enough power for one galley and if I put it in, you can see the galley is now powered by the trolley,” said  Ronny Knepple, head of energy systems at developer Diehl Aerospace. Diehl‘s humble-looking trolley houses a tank filled with liquid propylene glycol which provides the hydrogen – the fuel source for the battery.

“The propylene glycol from the tank is evaporated and here in the reformer at high temperature the hydrogen is extracted from the propylene glycol,” explains Professor Gunther Kolb from Fraunhofer Institute for Chemical Technology (Germany)  and one of the power unit’s designers.
A catalytic converter in the trolley transforms the toxic by-products of the reaction into carbon dioxide and water. And the compact unit is lighter and smaller than conventional energy systems.
We have used here our special plate heat exchanger technology, which allows us to reduce weight and especially the size of the system considerably. In some cases here, we could save 90 percent of the space required by conventional technology,” adds Prof. Kolb. Planes in service for decades are often refurbished with power-hungry new technology in their galleys. Diehl and its collaborators hope their system will provide an independent power source for increased energy demands. The prototype lighting up the galley in Paris could be seen on airliners within 2 years.

Source: http://www.diehl.com/

Nano In The Walls And Roofs Made Of Solar Cells

It isn’t cars and vehicle traffic that produce the greatest volumes of climate gas emissions – it’s our own homes. But new research will soon be putting an end to all that!  The building sector is currently responsible for 40% of global energy use and climate gas emissions. This is an under-communicated fact in a world where vehicle traffic and exhaust emissions get far more attention.

In the future, however, we will start to see construction materials and high-tech systems integrated into building shells that are specifically designed to remedy this situation. Such systems will be intelligent and multifunctional. They will consume less energy and generate lower levels of harmful climate gas emissions. With this objective in mind, researchers at SINTEF, a scientific institute located in Norway,  are currently testing microscopic nanoparticles as insulation materials, applying voltages to window glass and facades as a means of saving energy, and developing that prevent the accumulation of snow and ice. SINTEF researcher Bente Gilbu Tilset is sitting in her office  in Oslo. She and her colleagues are looking into the manufacture of super-insulation materials made up of microscopic nanospheres.


3D printed anal-house-by-DUS-Architects

Our aim is to create a low thermal conductivity construction material “, says Tilset. “When gas molecules collide, energy is transferred between them. If the pores in a given material are small enough, for example less than 100 nanometres in diameter, a molecule will collide more often with the pore walls than with other gas molecules. This will effectively reduce the thermal conductivity of the gas. So, the smaller the pores, the lower the conductivity of the gas“, she says.

While standard insulation materials such as mineral wools have conductivities in the region of 35 milliwatts per metre, nanospheres may exhibit values as low as about 20 mW/m. This is lower than the thermal conductivity of air. At present, these spheres are only available as a powder, but our dream is to aggregate them to form flexible mats.

In the future, nano-insulation materials such as these will enable us to reduce existing thicknesses. The mats will probably be more expensive than current products such as ‘Glava’, but will offer a better option in situations where space is at a premium such as in protected buildings where there are restrictions on making modifications to facades. They also work well as insulation materials for oil pipelines and industrial tanks.

 

Solar cells installed in panels fixed to our roofs and walls will be a thing of the past. Instead, they will be integrated into the roof tiles and external wall panelling materials. This will save on and construction costs, and will reduce electricity bills.

“In spite of Norway’s long, dark, winter nights, we are exposed to just as much daylight as Germany or the UK. A colder climate is in fact an advantage because solar cells are more effective in the cold. We reckon that this will become part of the Norwegian building tradition“, says physicist and SINTEF researcher Tore Kolås. Researchers are planning to look into how we can utilise solar cells as integral housing construction components, and how they can be adapted to Norwegian daylight and climatic conditions.

Source: http://phys.org/
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http://www.sintef.com/

Walking Again After Spinal Cord Injuries

Scientists at the Ecole Polytechnique Fédérale de Lausanne (EPFL)  in Switzerland proved in 2012 that electrical-chemical stimulation of the spinal cord could restore lower body movement in paralysed rats. Now they’re a step closer to making this a possibility for humans with spinal injuries. By applying so-called ‘surface implants‘ directly to the spinal cord, any movement or stretching of the nerve tissues could cause inflammation and, ultimately, rejection of the implant. This is their solution. Called e-Dura, it’s a soft and stretchy implant that can be bent and deformed similar to the living tissue that surrounds it.

EPFL SPINAL CORD REPAIRCLICK ON THE IMAGE TO ENJOY THE VIDEO

One important aspect of our studies is that we design the implant so that it could, one day, be used in a therapeutical context. So we wanted an implant that could stay for quite some time in vivo without inducing any detrimental effect. And so the first question we asked was: is soft making a difference?“, said Professor Stephanie Lacour, co-author of the study at EPFL.
E-Dura has a small tube through which neuro-transmitting drugs can be administered to the injured tissue to reanimate nerve cells. Built by on-site engineers, the device is made from silicon substrate covered with stretchable gold electric conducting tracks. Researchers found that when the prototype was implanted into rats’ spinal cords it caused neither damage nor rejection, even after two months. They concede, however, there is one significant hurdle to overcome.

There’s no link at the moment between the brain; so the motor command between the brain and the actual stimulation pattern on the spinal cord. So we now also have to find a way to link the two so that the person will think about moving and, indeed, the stimulation will be synchronised“, comments Prof. Lacour.
The team has set its sights on human clinical trails, and sees potential new therapies for e-Dura to treat conditions such as epilepsy, Parkinson’s disease and pain management.

Source: http://actu.epfl.ch/