March 21, 1901
Posted on 11/08/2013 10:12:29 AM PST by Red Badger
Using inexpensive materials configured and tuned to capture microwave signals, researchers at Duke University's Pratt School of Engineering have designed a power-harvesting device with efficiency similar to that of modern solar panels.
The device wirelessly converts the microwave signal to direct current voltage capable of recharging a cell phone battery or other small electronic device, according to a report appearing in the journal Applied Physics Letters in December 2013. (It is now available online.)
It operates on a similar principle to solar panels, which convert light energy into electrical current. But this versatile energy harvester could be tuned to harvest the signal from other energy sources, including satellite signals, sound signals or Wi-Fi signals, the researchers say.
The key to the power harvester lies in its application of metamaterials, engineered structures that can capture various forms of wave energy and tune them for useful applications.
Undergraduate engineering student Allen Hawkes, working with graduate student Alexander Katko and lead investigator Steven Cummer, professor of electrical and computer engineering, designed an electrical circuit capable of harvesting microwaves.
They used a series of five fiberglass and copper energy conductors wired together on a circuit board to convert microwaves into 7.3V of electrical energy. By comparison, Universal Serial Bus (USB) chargers for small electronic devices provide about 5V of power.
"We were aiming for the highest energy efficiency we could achieve," said Hawkes. "We had been getting energy efficiency around 6 to 10 percent, but with this design we were able to dramatically improve energy conversion to 37 percent, which is comparable to what is achieved in solar cells."
"It's possible to use this design for a lot of different frequencies and types of energy, including vibration and sound energy harvesting," Katko said. "Until now, a lot of work with metamaterials has been theoretical. We are showing that with a little work, these materials can be useful for consumer applications."
For instance, a metamaterial coating could be applied to the ceiling of a room to redirect and recover a Wi-Fi signal that would otherwise be lost, Katko said. Another application could be to improve the energy efficiency of appliances by wirelessly recovering power that is now lost during use.
"The properties of metamaterials allow for design flexibility not possible with ordinary devices like antennas," said Katko. "When traditional antennas are close to each other in space they talk to each other and interfere with each other's operation. The design process used to create our metamaterial array takes these effects into account, allowing the cells to work together."
With additional modifications, the researchers said the power-harvesting metamaterial could potentially be built into a cell phone, allowing the phone to recharge wirelessly while not in use. This feature could, in principle, allow people living in locations without ready access to a conventional power outlet to harvest energy from a nearby cell phone tower instead.
"Our work demonstrates a simple and inexpensive approach to electromagnetic power harvesting," said Cummer. "The beauty of the design is that the basic building blocks are self-contained and additive. One can simply assemble more blocks to increase the scavenged power."
For example, a series of power-harvesting blocks could be assembled to capture the signal from a known set of satellites passing overhead, the researchers explained. The small amount of energy generated from these signals might power a sensor network in a remote location such as a mountaintop or desert, allowing data collection for a long-term study that takes infrequent measurements.
Wasn’t tesla working on a device to collect and use static electricity when he passed on?
March 21, 1901
He was, IIRC...........
I agree....
Plus this press release puts spin on (for the science deprived) as if they have a lead on microwave cells that would be like solar cells. Collecting-harvesting large amounts of free energy. Where is the free microwave energy? Not too many natural sources. This innovation will collect from meager man made sources (looks to me)
Put it near your m-wave oven and charge your cell phone?
May I be added to the Galt ping list.
I think I would go for the motor that works on magnetism.
http://freeenergynews.com/Directory/Howard_Johnson_Motor/
tesla was right.
Watch the Big $$$ power companies buy the patents, and kill it deader than Vince Foster in Fort Marcy park!
And when he died FDR’s goons swept in and disappeared all his papers. For the betterment of all, of course.
I briefly looked into the idea of a passive receiving antenna on the nearby hilltop with a cable leading to a passive transmitting antenna located in the basement.
The problem I saw was that the FCC would probably get on my case for having re-transmitted this signal and the pager company would also be concerned because the receiving antenna would create an area of low signal strength behind the antenna, perhaps depriving other customers of the paging company from receiving their signals.
I can see a similar problem with the devices being suggested in this article. If a room full of people are soaking up the energy from a Wi-Fi there might be just that much less for the folks expecting a connection to the internet. I see much regulation ahead.
Aren't there places with little or no magnetic field?
I'm waiting for the further development in Brazil of a gravity motor. I don't ever remember not having more than enough gravity. Their company motto will no doubt be, "The motor for people who will fall for anything".
to convert microwaves into 7.3V of electrical energy. By comparison, Universal Serial Bus (USB) chargers for small electronic devices provide about 5V of power.
Oooooo, volts. How about power instead.
Consider a powerful AM station like WLW (50 kilowatt transmit power). At 1 km away, assuming no atmospheric absorption and and omnidirectional pattern (not true but good for a first estimate), you would have an energy flux of about 4 milliwatts per square meter. Now consider that most of the transmitters they are talking about are in the milliwatt to watt range instead of 50 kW.
Compare that to solar which has an energy flux of about 1 kilowatt / square meter at ground level on a sunny day.
Discovered in the ruins of the Twentieth Century Motor Company in Starnesville, Wisconsin.
Starnesville - Detroit.
They mention vibrations being useful to create power. I wonder if wind power could be used to vibrate materials that are attached to dynamos to create power verses using spinning turbines that kill birds! Imagine “wires” with a series of attached discs that “flutter” as the wind passes thru. The wire transmits all that kinetic energy to a sub dynamo that creates current which is collected via huge capacitors then sent out onto the grid . The discs could be connected by guide wires so that they flutter with some coherency to increase efficiency of the kinetic energy to be transferred. The height of the unit and/or the use of multiple grids of these strings in a collector allow a scaling of power collected per unit allowing decent power collection in low breeze conditions and vent dampeners could be used to moderate flows in potentially damaging high wind events.
Now my betters might could use math to tell one if such a system could be made to produce power efficiently based on equipment costs; but it seems to me that any power produced at all is better than no power at all when a shtf knocks out services over a wide area.
There is power in a plucked string of a violin that can sooth the soul. Perhaps a power system comprised of “wind plucked strings” connected to electrical dynamos can be scaled up to provide a useful niche in off the grid power production systems. Perhaps we could call such a system a “harp” system, with no relation to the “spook system” the military runs.
Google ‘VERTICAL WINDMILL IMAGES’.....There are lots of windmill designs out there that will not kill birds.................
Ding! Ding! Ding!
I believe we have a winner.
I'm sure the NSA is thrilled at the prospect.
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