HOW WIRELESS POWER WORKS  1. Magnetic coil (Antenna A) is housed in a box and can be set in wall or ceiling. 2. Antenna A, powered by mains, resonates at a specific frequency. 3. Electromagnetic waves transmitted through the air. 4. Second magnetic coil (Antenna B) fitted in laptop/TV etc resonates at same frequency as first coil and absorbs energy. 5. Energy charges the device. |
Friday, August 27, 2010
HOW WIRELESS POWER-Witricity WORKS
To harness power from lightning...A controversy !
Tiny charges gathered directly from humid air could be harnessed to generate electricity, researchers say.
Dr Francesco Galembeck told the American Chemical Society meeting in Boston that the technique exploited a little-known atmospheric effect.
Tests had shown that metals could be used to gather the charges, he said, opening up a potential energy source in humid climates.
However, experts disagree about the mechanism and the scale of the effect.
"The basic idea is that when you have any solid or liquid in a humid environment, you have absorption of water at the surface," Dr Galembeck, from the University of Campinas in Brazil, told BBC News.
"The work I'm presenting here shows that metals placed under a wet environment actually become charged."
Dr Galembeck and his colleagues isolated various metals and pairs of metals separated by a non-conducting separator - a capacitor, in effect - and allowed nitrogen gas with varying amounts of water vapour to pass over them.
What the team found was that charge built up on the metals - in varying amounts, and either positive or negative. Such charge could be connected to a circuit periodically to create useful electricity.
The effect is incredibly small - gathering an amount of charge 100 million times smaller over a given area than a solar cell produces - but seems to represent a means of charge accumulation that has been overlooked until now.
Dr Galembeck suggests that with further development, the principle could be extended to become a renewable energy resource in humid parts of the world, such as the tropics.
Charged debate
However, while the prospect of free electricity from the air is tantalising, the prospect of harnessing enough of it to be widely useful is still a matter of some debate.
Hywel Morgan of the University of Southampton says that a similar effect has been known for some time; he points out that tribocharging - the generation of charge by rubbing wool over amber or water droplets over water droplets - is the origin of thunderstorms.
"What we think is happening is he's pumping the water vapour across his capacitor and during the pumping mechanism, tribocharging the water vapour."
That would result in a charge, but would not be the same as simply pulling the charge from still, wet air.
Marin Soljacic, the Massachusetts Institute of Technology physicist behind a wireless power transmission technology, known as Witricity, disagrees.
He calls the paper "very interesting" and "a good area of research".
He concurs, however, that the amount of charge gathered in the initial tests suggests the effect may be difficult to put to good use, saying that "at this point it is far-fetched to see how it could be used for everyday applications".
"It really warrants future research and understanding what all the limitations of this are, how far it can go," he told BBC News.
"[Prof Morgan] is right that a similar and closely-related effect is known to exist, but we're very pressed for finding new sources of renewable energy, [so] I think it's a bit early to discard this research."
Dr Galembeck is familiar with the controversy that this kind of work generates, saying that disagreement about the mechanism behind it forms "the motif for bitter discussions among scientists".
"There have been many attempts to harness electricity from the atmosphere and most had bad endings."
source:BBC
Wednesday, August 18, 2010
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Wednesday, August 11, 2010
Human brain on a microchip nearly ready - University of Calgary
Toronto: The human brain on a microchip is almost ready!
Turning into reality science fiction of films such as "The Terminator" - where machines and men meld into reality - Canadian scientists have successfully connected brain cells to a silicon chip to "hear" conversation between brain tissue.
The neuro-chip, which has been developed by medicine scientists at the University of Calgary, will network brain cells and thus record brain cell activity at a resolution never achieved before, according to Naweed Syed who led the team that made the breakthrough.
The neuro-chip will help future understanding of how brain cells work under normal conditions and thus permit drug discoveries for a variety of neuro-degenerative diseases such as Alzheimer's and Parkinson's, a university statement said Tuesday.
"This technical breakthrough means we can track subtle changes in brain activity at the level of ion channels and synaptic potentials, which are also the most suitable target sites for drug development in neuro-degenerative diseases and neuropsychological disorders," Syed, who is professor and head of the Department of Cell Biology and Anatomy, has been quoted as saying.
The new neuro-chips are also automated.
"Previously it took years of training to learn how to record ion channel activity from brain cells, and it was only possible to monitor one or two cells simultaneously. Now, larger networks of cells can be placed on a chip and observed in minute detail, allowing the analysis of several brain cells networking and performing automatic, large-scale drug screening for various brain dysfunctions," the university statement said.
The University of Calgary is excited at the potential of this made in Canadatechnology, said university vice president Rose Goldsmith.
"The University of Calgary is proud to be the home of this cutting edge Canadian work with a neurochip. The advances in research and healthcare made by possible by this technology are immense. The work and collaboration happening in the lab of Naweed Syed is another example demonstrating our leadership in the field of biomedical engineering."
The new technology has been published online this month in the journal, Biomedical Microdevices. IANS
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