Think about a place where humans cannot easily go but a crab-walker made of paper and polystyrene can go easily. Scientist has been working lately on making such kind of robots to reach the places where humans never imagined reaching.

At first sight, it looks like a child’s science fair project: a flat, plastic cutout with batteries in the middle. Then it shudders to life. A few joints bend. The midsection rises with a startling jolt. Moments later, it scuttles away.

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This crab-walker — which self-assembles from about $20 worth of parts and walks without human direction — marks an advance in inexpensive and versatile robotics that could ultimately be created for pennies, stacked like a deck of cards and deployed in spaces and applications where no robot has gone before.

Researchers at Harvard and MIT created a robot and their work was published in Science in August.  This robot is made of paper and 3-D sheets of polystyrene from the children’s art toy Shrinky Dinks. To allow the robot to fold like a piece of origami or unfold like a flower petal embedded wires were used. This embedded wires heat and shrink the material in certain places.

Just about every manner of nanoparticle and nanomaterial has been applied to polymer solar cells.  Despite all of this work, conversion efficiencies for single p-n junction polymer solar cells are mired at around 9 percent, while cells with more than one p-n junction havemustered efficiencies only as high as 10.6 percent.

All those frustrated efforts made it reasonable to wonder whether nano particles would ever provide much of a boost to polymer solar cells.

Now, an X-ray study performed at the Deutsches Elektronen-Synchrotron (DESY) by a team from the Technical University of Munich (TUM) using DESY’s synchrotron radiation source, PETRA III, has demonstrated that magnetic nanoparticles can improve the performance of polymer solar cells—if the mix is right.

In research published in the journal Advanced Energy Materials, the German-based researchers demonstrated that by making sure the solar cell material contains just about one percent of magnetic nano particles by weight, they were able to boost the solar cell’s efficiency.

“The X-ray investigation shows that if you mix a large number of nanoparticles into the material used to make the solar cell, you change its structure”, explains coauthor Stephan Roth, who runs DESY’s microfocus small- and wide-angle x-ray scattering beamline at PETRA III, in a press release. “The solar cells we looked at will tolerate magnetic nanoparticle doping levels of up to one percent by mass without changing their structure.”

How to exploit the nanoparticles is where the Germany-based researchers departed from recent research. Solar cell material doped with gold nanoparticles had already been demonstrated to absorb additional sunlight—which, in turn, produced additional electrical charge carriers when the energy was released again by the gold particles.

“The light creates pairs of charge carriers in the solar cell, consisting of a negatively charged electron and a positively charged hole, which is a site where an electron is missing,” explained the main author of the current study, Daniel Moseguí González, in a press release. “The art of making an organic solar cell is to separate this electron-hole pair before they can recombine. If they did, the charge produced would be lost. We were looking for ways of extending the life of the electron-hole pair, which would allow us to separate more of them and direct them to opposite electrodes.”

To extend the life of the electron-hole pair, the researchers exploited the spin of the electrons. The positively charged hole also has a spin. If the two spins are in the same direction, they can add up to a value of one, or cancel each other out, for a value of zero, if they are oriented in opposite directions. Pairs that have an overall spin value of one last longer than those that have an overall spin of zero.

The key was finding a material capable of converting an electron-hole pair’s overall spin state from zero to one. To accomplish this, the researchers needed nanoparticles made from heavy elements, because they can flip the spin of the electron or the hole so that spins are aligned in the same direction.

The material they hit upon was iron oxide magnetite. By adding just the right amount of the magnetite (doping the substrate with 0.6 percent nanoparticles by weight) they were able to increase the energy conversion efficiency by 11 percent, from 3.05 to 3.37 percent.

“The combination of high-performance polymers with nanoparticles holds the promise of further increases in the efficiency of organic solar cells in the future,” said Peter Müller-Buschbaum of TUM in the release. “However, without a detailed examination, such as that using the X-rays emitted by a synchrotron, it would be impossible to gain a fundamental understanding of the underlying processes involved.”

Source:EEE Press

Perovskites are not a material, but a crystalline structure that many compounds can assume, here made from lead, iodide and methylammonium at Stanford University (Palo Alto, Calif.) The researchers claim that their perovskites can harvest the high-energy photons that silicon solar cells miss, resulting in unwanted heat, allowing the output of normal silicon cells to be multiplied.

In the lab, the researchers claim to have achieved 17% efficiency by stacking a perovskite solar cell atop a cheap silicon cell rated at 11.4%. When stacking a perovskite solar cell atop a copper indium gallium diselenide (CIGS) cell they achieved a 18.6% efficiency.

The downside is that perovskite are fragile, dissolving in water and continuously degrading in light, nothing even close to the 25-year lifespan of silicon solar cells. Nevertheless, the Stanford researchers are working on making them more durable with a goal of a 25-year lifespan and 30% efficiency in five to 10 years.

Source: EEE Press

At present internet is the main medium of communication. So scientists are given their 100% effort to increase the internet speed. Think how remarkable it will be if the internet speed increased 1000 times faster. It might be possible in near future, Because Artemis Networks working on a new high speed pCell Wireless Technology which will give users Internet speed 1000 times faster than 4G/LTE networks

SIM’s with pCell Wireless Technology to be available in San Francisco.

Entrepreneur Steve Perlman who is well known for his invention of Web TV has now come up with a new pCell Wireless Technology which can help in accelerating the speed of internet on smartphones.

Researchers at Perlman’s new start up Artemis Networks; just a 3 year old baby, have come up with a pCell Wireless Technology which can provide about 1000 times greater internet speed as compared to 4G/LTE networks.

A SIM card needs to purchase by the consumers from Artemis Network’s website to get their phones connected to pCell network. The users who use internet on smart phones have seen the conventional speeds of the internet from 2G to 3G to now 4G however pCell Wireless technology claims to provide 1000 times better speed than 4G networks and also boast to wipe out the “call drops” in busy places,meetings or stadiums, private areas which are normally offline due to unavailability of phone network.

The apprehensive wireless industry needs proof to believe this and hence Perlman is going to build a network of pCell Wireless Technology using DISH Network’s spectrum at San Francisco. For San Fransisco users who have an unlocked iPhone 6 or iPad Air 2, the Artemis SIM cards can be directly inserted in the device.

Apples unlocked iPhones come with all spectrum bands built-in where Android smartphones have limited spectrum band options. Because of that for now Apple’s iPhone are the best option for pCell to work.

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Normally gigantic signals emitted by the huge traditional cell towers are shared by the phones within that cell or area. But pCell network is built by “hotspot like” devices known as pWaves which emit the radio waves. To cover huge areas, the traditional cell towers are spaced far off and their waves do not interfere each other.however in pCell the pWaves are purposely spaced in such a way so that the radio waves collide with each other which helps to create an individual network for each user.

So basically Artemis would be using the criss-crossing of these radio waves to provide a higher availability of the cellular network to its users. Also as against the traditional cell towers which are huge and take a lot of space the pWaves are small, about the size of wireless router and hence can be placed anywhere.

Perlman has plans to use the rooftops in San Francisco to deploy pWaves and due to the smaller size of this unit the overall cost of its infrastructure would be greatly reduced. He told Business Insider that larger numbers of pWaves will be placed in such a way that pCell Wireless Network can cover the area more accurately as compared to the traditional cell tower.

Perlman has plans to set up the pCell network at San Francisco first to prove his concept to the wireless industry as he sees future tie ups with the other larger carriers in other cities for pCell.

Since he is launching the pCell network only in San Francisco for now, the Artemis Networks SIM card will work on the Mobile Virtual Network Operator or MVNO network in cases when the user goes out of city limits. Basically MVNO networks are not self-owned service providers and larger carriers lease out their spectrum to these MVNO. MVNOs are well known for providing voice and data serviced at lower and flexible rates.

pCell is still awaiting Federal Communications Commission (FCC) approvals and the MVNO tie up formalities. Artemis Networks has plans to go live by this fall or early next year. Perlman has assured that Artemis Network will provide different plans option for its users with unlimited data plan which will cost much lower than what the conventional carriers are charging and this will be due to the lower infrastructure and capital expenses.

However he has refused to divulge the plan rates as of now. Artemis Networks also has plans to provide device similar to a MiFi wireless router which will provide wireless network at homes. The Artemis I Hub, will be available for some mobile operators for trial from Tuesday.

An innovative approach by the Artemis team is really need of the hour as internet is becoming part and parcel of day to day life so some out of the box idea which will save the user’s pocket along with providing higher internet speed is truly incredible.

The price of going solar is dropping dramatically, with rooftop solar systems costing around 80 percent less today than in 2008. Panels are getting cheaper and easier to mass-produce, and the technology is becoming more efficient at turning sunbeams into clean electricity. In some parts of the United States, solar power is actually cheaper than conventional fossil fuel energy.Solar energy is having a moment.

Plunging costs are allowing more Americans to put photovoltaic panels on their rooftops. Nearly 200,000 homes and businesses added on-site solar projects last year, bringing the country’s total count to more than 600,000, according to a recent industry report. Across all solar sectors, companies installed a record 6,200 megawatts of PV capacity in 2014 — a 30 percent jump over the previous year. By 2020, developers worldwide are expected to spend more than $134 billion annually on solar energy systems, up by more than 50 percent compared to 2013, according to Navigant Consulting Inc.

Perhaps no project better captures the industry’s achievements than the Solar Impulse 2, the panel-powered aircraft currently circumnavigating the globe and set to land on U.S. soil this spring. Solar experts say the Impulse mission shows the public just how far PV technology has advanced.

With the solar plane, “We’re able to do something we weren’t able to even 10 years ago,” said Neil Abrams, a professor and solar energy researcher at the State University of New York’s College of Environmental Science and Forestry in Syracuse.

This revolutionary single-seater aircraft made of carbon fiber has a 72 meter wingspan (larger than that of the Boeing 747-8I) for a weight of just 2,300 Kg, equivalent to that of a car.The 17,000 solar cells built into the wing supply four electric motors (17.5 CV each) with renewable energy.During the day, the solar cells recharge lithium batteries weighing 633 Kg (2077 lbs.) which allow the aircraft to fly at night and therefore to have virtually unlimited autonomy.

Gregory Wilson, who directs the U.S. Department of Energy’s National Center for Photovoltaics in Golden, Colorado, said the aircraft showcases the best of existing solar technology. Solar cells on the plane are about twice as efficient at turning sun rays into electricity as a typical household model. The cells themselves are flexible and wrap around the plane’s wings, unlike the stiff, flat rectangles used in most rooftop systems. The aircraft’s battery storage system makes it self-sufficient, whereas most buildings with solar panels still rely on the utility grid to keep the lights on around the clock. “It shows that those technologies are just right out there beyond our fingertips, but could start becoming real [for consumers] within a couple of years,” Wilson said.

Two Swiss pilots, Bertrand Piccard and André Borschberg, are leading the airborne mission, which launched March 9 from Abu Dhabi in the United Arab Emirates. Now the world’s only solar-powered aircraft ‘Solar Impulse-2′ is all set to fly to Varanasi on Wednesday 18th March after a week’s stopover in Ahmedabad as part of its round-the-world trip.

“Only ten hours left before Solar Impulse-2 take off from Ahmedabad with Andre Borschberg at the controls in Flight three on round-the-world trip with zero fuel,” the ‘Solar Impulse-2′ (SI-2) team tweeted on Tuesday.

German test pilot Markus Scherdel (C) poses with Solar Impulse co-founders Andre Borschberg (R) and Bertrand Piccard after taking the solar-powered Solar Impulse 2 aircraft on its maiden flight at its base in Payerne June 2, 2014. Photo: Reuters

Earlier, the SI-2 team had postponed departure from its scheduled date on March 15 due to bad weather conditions. Later, it was scheduled for departure on March 17, which was extended by one more day until March 18.

The globe-trotting SI-2 landed at the SardarVallabhai Patel International Airport in Ahmedabad on March 10, around 15 hours after it took off from Muscat. Andre Borschberg, the project’s co-founder and pilot, besides its co-pilot as well as president Bertrand Piccard have spent more than a week in the city.

The aircraft began its journey on March 9 from Abu Dhabi. Swiss pilot Bertrand Piccard had flown the plane from Muscat to Ahmedabad, while his co-pilot Borschbergh will fly the solar-powered aircraft to Varanasi. From Varanasi, the SI-2 is scheduled to fly to Mandalay in Myanmar, Chongqing and Nanjing in China and thereafter to the USA.

The massive adoption of solar power and other renewable energy resources is critical for fighting climate change. Scientists say the world must reduce emissions of greenhouse gases to 80 percent below 1990 levels within the next four decades in order to keep the planet from warming by 2 degrees Celsius (3.6 degrees Fahrenheit). To achieve those reductions, most of the world’s remaining oil, coal and natural gas will have to stay in the ground, global climate experts agree.

Yet only about 21 percent of the world’s electricity generation comes from renewable energy and hydropower at this point, according to U.S. energy statistics. Solar PV systems account for only a sliver of that amount.

If countries boosted solar output to 20 percent of total energy production by 2025, global emissions would drop by around 19 percent, Wilson said. “Solar is almost certainly going to be the most significant technology in the next 20 years for taking carbon out of our electricity system,” he said. The Solar Impulse, he added, “at least is going to get the public asking the right questions about energy supplies.”

Iowa State Aerospace Engineers Anupam Sharma and Hui Hu are exploring the possibility of adding a smaller, secondary rotor to wind turbines. The engineers studied the base of existing turbines and found two major problems. First, they are big round structural pieces that don’t harvest any wind energy because they are not shaped like an airfoil. Second, the large base of the blades actually disrupt the wind, causing a wake behind them which reduces the energy harvesting capacity of any downwind turbines. Hu says that a turbine in the slipstream of another “can lose 8 to 40 percent of its energy production, depending on conditions.”

Their solution? Add a second, smaller rotor. “To try to solve these problems, we put a small rotor on the turbine,” Hu said. “And we found that with two rotors on the same tower, you get more energy.” Lab tests and computer simulations found the extra blades and increase the energy harvest by up to 18 percent. “These are fairly mature technologies we’re talking about – a 10 to 20 percent increase is a large change,” Sharma said.

Using a one-year, $116,000 grant from the Iowa Energy Center, the pair is currently using wind tunnels and computer simulations to study the dual rotor idea and measure power outputs and wind loads. The questions they hope to answer are: How is the wake distributed? Where are the whirling vortices? How could the wake be manipulated to pull down air and recharge the wind load?

They plan to use the research results to find the best aerodynamic design for a dual-rotor turbine. The goal is to find out where the second rotor should be located, how big it should be, what kind of airfoil it should have, and if it should rotate in the same direction or in the opposite direction.

The above image (courtesy of Anupam Sharma) shows air flowing through a dual-rotor turbine. Read more details about the research over at the Iowa State website.

What do you think? Could a second rotor make wind turbines more efficient? Leave your comments below…

Source: Click Here