VGC Physics

25/05/2018

Destination Guides

03/03/2018

• Stretchy Artificial 'Skin' Could Give Robots a Sense of Touch •

Rubber electronics and sensors that operate normally even when stretched to up to 50 percent of their length could work as artificial skin on robots, according to a new study. They could also give flexible sensing capabilities to a range of electronic devices, the researchers said.

Like human skin, the material is able to sense strain, pressure and temperature, according to the researchers.

Yusaid the rubber electronics and sensors have a wide range of applications, from biomedical implants to wearable electronics to digitized clothing to "smart" surgical gloves.

Because the rubbery semiconductor starts in a liquid form, it could be poured into molds and scaled up to large sizes or even used like a kind of rubber-based ink and 3D printed into a variety of different objects, Yu told Live Science.

One of the more interesting applications could be for robots themselves, Yu said. Humans want to be able to work near robots and to coexist with them, he said. But for that to happen safely, the robot itself needs to be able to fully sense its surroundings. A robot — perhaps even a soft, flexible one, with skin that's able to feel its surroundings—could work side by side with humans without endangering them, Yu said.

In experiments, Yu and his colleagues used the electronic skin to accurately sense the temperature of hot and cold water in a cup and also translate computer signals sent to the robotic hand into finger gestures representing the alphabet from American Sign Language.

Electronics and robots are typically limited by the stiff and rigid semiconductor materials that make up their computer circuits. As such, most electronic devices lack the ability to stretch, the authors said in the study.

In research labs around the world, scientists are working on various solutions to produce flexible electronics. Some innovations include tiny, embedded, rigid transistors that are "islands"in a flexible matrix. Others involve using stretchy, polymer semiconductors. The main challenges with many of these ideas are that they're too difficult or expensive to allow for mass production, or the transmission of electrons through the material is not very efficient, Yu said.

This latest solution addresses both of those issues, the researchers said. Instead of inventing sophisticated polymers from scratch, the scientists turned to low-cost, commercially available alternatives to create a stretchy material that works as a stable semiconductor and can be scaled up for manufacturing, the researchers wrote in the study.

Yu and his colleagues made the stretchable material by mixing tiny, semiconducting nanofibrils — nanowires 1,000 times thinner than a human hair — into a solution of a widely used, silicon-based organic polymer, called polydimethylsiloxane, or PDMS for short.

When dried at 140 degrees Fahrenheit (60 degrees Celsius), the solution hardened into a stretchable material embedded with millions of tiny nanowires that carry electric current.

The researchers applied strips of the material to the fingers of a robotic hand. The electronic skin worked as a sensor that produced different electrical signals when the fingers bent. Bending a finger joint puts strain on the material, and that reduces electric current flow in a way that can be measured.

For example, to express the sign-language letter "Y," the index, middle and ring fingers were completely folded, which created a higher electrical resistance. The thumb and pinky fingers were kept straight, which produced lower electrical resistance.

Using the electrical signals, the researchers were able spell out "YU LAB" in American Sign Language.

Yu said he and his colleagues are already working to improve the material's electronic performance and stretchiness well beyond the 50 percent mark that was tested in the new study.

Source :- livescience

04/08/2017

Have Proud On BHARAT MATA
Be PATRIOTIC
Say VANDEMATARAM
have pround on MARTYRS
SALUTE them
KYUKI DESH RAHEGA TABHI TUM RAHOGE
Kick the butt of so called gaddars who hesitate to say BHARAT MATA KI JAI or VANDE MATRAM
have proud you are in the Oldest and Foremost Cultures!!!!!
Jai Shree Ram , Jai Hind, Jai Hindu!!

14/07/2017

Physicists have just discovered a new form of light that doesn't follow our existing rules of angular momentum, and it could shake up our understanding of the electromagnetic radiation and lead to faster, more secure optical communication.

Because of how well-studied and, well, everywhere, light is, you might assume that we've pretty much learnt all there is to know about it. But just last year, researchers identified a fundamental new property of light, and now a team of Irish scientists has shown that light can take on unexpected new forms.

One of the ways we measure a beam of light is through its angular momentum - a constant quantity that measures how much light is rotating. And until now, it was thought that for all forms of light, the angular momentum would be a whole number (known as an integer) multiple of Planck's constant - a physical constant that sets the scale of quantum effects.

But researchers led by Trinity College Dublin have now demonstrated that a new form of light exists, where the angular momentum is only half of this value.

"What I think is so exciting about this result is that even this fundamental property of light, that physicists have always thought was fixed, can be changed," said lead researcher Paul Eastham.

Let's back up for a second here and explain what all that means.

As one of the researchers, Kyle Ballantine, explains:

"A beam of light is characterised by its colour or wavelength and a less familiar quantity known as angular momentum. Angular momentum measures how much something is rotating. For a beam of light, although travelling in a straight line, it can also be rotating around its own axis. So when light from the mirror hits your eye in the morning, every photon twists your eye a little, one way or another."

As mind-bending as that might sound, it's all well understood by physicists. But what they didn't realise was that light could exist that had an angular momentum that wasn't a whole number.

To figure this out, the team passed light through crystals to create beams of light that had a twisted, screw-like structure. They were looking for new light behaviours that might improve optical communications, but when they analysed this particular beam within the theory of quantum mechanics, it looked as though its angular moment would be a half-number - which definitely wasn't what they'd expected to find.

They then came up with an experiment to test this prediction, and were able to construct a device that measured the flow of angular momentum within the light beam, as well as the variation in this flow caused by quantum effects.

Usually any of those quantum variations would cause the angular moment to change by whole numbers, based on our understanding of physics so far. But the experiments revealed a tiny shift - one-half of Planck's constant - in the angular momentum of each photon.

That's really exciting, not only because it's a brand new form of light, but because since the 1980s, theoretical physics have predicted that quantum mechanics would enable the possibility of particles whose quantum numbers were fractions of those expected. And now, for the first time, this work proves those predictions right, using one our best-studied particles.

"The topic of light has always been one of interest to physicists, while also being documented as one of the areas of physics that is best understood," said one of the researchers, Stefano Sanvito. "This discovery is a breakthrough for the world of physics and science alike."

The biggest impact, other than shaking up our understanding of light, is that this new information could help to improve speed and security along fibre-optic cables, leading to faster, safer internet connections.

But before we get anywhere close to benefitting from this new form of light, another team of researchers will need to replicate and validate this work to make sure it wasn't just a one-off. Science is often a slow process, but there's no denying its an exciting one.




Source :- sciencealert.com

10/05/2017

01/01/2017

Wish you a happy new year guys

06/07/2016

Conversion table of CGPA to equivalent percentage

Equivalent % = [ CGPA * 11 ] - 12

25/06/2016

If you in
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have
and
and ,
'll be a .
The of is but so are the .

01/01/2016

Happy New Year 2016 Everyone
May this year will be filled with happiness..

11/11/2015

Wish you happy Diwali guys

11/11/2015

Wish you happy Diwali guys