Beta

Slashdot: News for Nerds

×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

Radio Energy Harvested With Inkjet-Printed Antenna

samzenpus posted more than 2 years ago | from the catching-the-waves dept.

Power 164

judgecorp writes "Everlasting green energy for RF tags and other low-power devices could be possible as scientists have harvested energy from ambient radio waves using cheap antennas printed by an ordinary inkjet. The scientists, from Georgia Tech, started at 100MHz but have now produced systems which scavenge power at up to 60GHz, allowing them to draw power from most of today's major radio technologies."

cancel ×

164 comments

So they're using background radiation only? (3, Insightful)

Anonymous Coward | more than 2 years ago | (#36942390)

Because it seems like if you want to power these things, they need to use power from a radio source. Which doesn't make them green at all.

Re:So they're using background radiation only? (1, Informative)

Ethanol-fueled (1125189) | more than 2 years ago | (#36942404)

The shape is also a little awkward, if you read TFA. There's only one place [blogspot.com] where it could be placed for maximum efficiency.

Re:So they're using background radiation only? (0, Offtopic)

Anonymous Coward | more than 2 years ago | (#36942480)

At least that wasn't goatse.

Re:So they're using background radiation only? (5, Informative)

icebike (68054) | more than 2 years ago | (#36942440)

Because it seems like if you want to power these things, they need to use power from a radio source. Which doesn't make them green at all.

The radio source is there all the time anyway, It is there for other uses.

But as should be obvious, the vast majority of radio waves are never used, being disparate over vast distances or absorbed by the earth itself. Utilizing this "wasted" energy costs nothing, because we are already emitting that energy, and utilizing it costs no more. At the emitter you can't measure if a radio wave hits one antenna or a million antennas. Its no different to you as the sender of that wave.

So by using freely available wasted energy these devices obviate the need for ANOTHER power source and are therefor green.

unless the entire term 'green' (1)

decora (1710862) | more than 2 years ago | (#36943070)

is completely and utterly vague, and has become like 'fascist' or 'capitalist' or 'communist', a word without any actual, real meaning.

Re:unless the entire term 'green' (1)

Ohrion (814105) | more than 2 years ago | (#36943638)

Stop using arguments against useless buzzwords!!!

Re:So they're using background radiation only? (0)

Anonymous Coward | more than 2 years ago | (#36943708)

At the emitter you can't measure if a radio wave hits one antenna or a million antennas.

Well, not if the systems isn't designed to do it but many RFID systems uses load modulation to signal back to the transceiver.
If other systems uses this energy to power themselves and doesn't use a constant or LF enough load they may interfere with this communication.

Re:So they're using background radiation only? (5, Interesting)

fuzzyfuzzyfungus (1223518) | more than 2 years ago | (#36942514)

Because it seems like if you want to power these things, they need to use power from a radio source. Which doesn't make them green at all.

They do, indeed, consume some energy from the RF broadcast(in principle, if you really chaffed the place with them, the reduction in SNR might actually be noticeable by devices trying to communicate...) However, there are two other considerations:

1. Particularly in classic broadcasting(less your fancy 802.11-draft-whatever-with-beamforming-and-a-line-of-sight-yadda-yadda smart antenna nonsense) a substantial amount of broadcast power just floats away into the aether, never to be snagged by any receiver. So long as you are(by making receivers super cheap) just burning through some of this formerly wasted power, the energy counts as "free". Not until your piggybacking requires the towers to start cranking it up is their a cost.

2. If the deployment of some distributed-sensor net widgetry is an inevitability(there are legimitate grounds for question at this point; but we generally don't take advantage of them) it has to be powered somehow. The major contenders are A. Lithium primary cells: unless somebody plans on cleaning the whole thing up a decade from now, the delightsome battery goo is going straight into the environment. B. Photovoltaics(in suitably sunlit locations that are OK with sporadic power): the energy generation itself is clean, the manufacturing and some of the components are rather less so. C. Piezoelectrics: not all of the suitable candidates contain lead; but a lot of the common ones really ought to be collected after use.

In our brutally entropic universe, nothing is truly "green"; but it is quite possible that RF harvesting will prove to be green-er and/or more convenient in some applications.

Re:So they're using background radiation only? (0)

Anonymous Coward | more than 2 years ago | (#36943632)

There is a fundamental law that this is breaking, making it impossible to implement. There is no way to put a brand name on the radio wave that would be decoded, and passed on to the user as an ad. This makes the practice unprofitable, unregulated, nontaxable, a waste of trees and therefore environmentally irresponsible, well, and just plain goddam smart (and we do NOT want that). Therefore to prevent this, I'm contacting a lawyer at this moment to have the idea patented. Then I will sell the patent to a troll. As of then anyone caught using this technology will be fined a licensing fee. If you refuse, the law will confiscate your printer. And your brain (this may contain illegal copies of the patented technology). And your paper so you can't print. Then we'll atomize this planet to tiny bits! Because we know its your favorite thing.

Re:So they're using background radiation only? (2)

WrongSizeGlass (838941) | more than 2 years ago | (#36942674)

So they're using background radiation only?

No, they'll end up using radio waves sent out by radio stations ... at least until the RIAA finds out they're not paying royalties and sues them into oblivion.

Re:So they're using background radiation only? (2)

X0563511 (793323) | more than 2 years ago | (#36943182)

You'd be using the carrier wave, which contains no information in and of itself.

It's only the angle-demodulated signal that contains RIAA verboten information.

(yea... FM broadcasts are NOT SSBSC, so eat me)

Re:So they're using background radiation only? (1)

hitmark (640295) | more than 2 years ago | (#36943430)

"No officer, i am not listening to music. I am collecting energy".

Re:So they're using background radiation only? (1)

Divebus (860563) | more than 2 years ago | (#36943262)

It'll work great until Epson figures out how to keep them from refilling the ink cartridges...

radio harvested with piece of rock (galena) (5, Informative)

YesIAmAScript (886271) | more than 2 years ago | (#36942394)

It's called a crystal radio.

A diode does it too.

Re:radio harvested with piece of rock (galena) (1)

Anonymous Coward | more than 2 years ago | (#36942560)

I'm not an electrician, but I'm pretty sure the antenna turns the radio waves into a current, you just add a diode/crystal to it to make sure the current is all flowing in the same direction.

Re:radio harvested with piece of rock (galena) (4, Informative)

fuzzyfuzzyfungus (1223518) | more than 2 years ago | (#36942594)

It's called a crystal radio.

A diode does it too.

The "offtopic" is hardly fair, RF-energy harvesting(conveniently combining the signal and the power) found its first major application in early AM radio setups. TFA, though, focuses on advances in antenna design and fabrication that allow much more compact, and far broader-spectrum energy harvesting. The AM antennas of yore, particularly in designs without any amplifiers available, were often not exactly monuments to compactness...

Can it power a cellphone? (1)

n2rjt (88804) | more than 2 years ago | (#36942446)

It would be cool to power a cellphone with this. I don't mean transmit, silly, but the receive side, while otherwise asleep.

Re:Can it power a cellphone? (2)

DrBuzzo (913503) | more than 2 years ago | (#36942510)

No, no it can't. The power density of ambient RF energy is nowhere near enough to run even the basic circuitry of a phone. Sorry.

Re:Can it power a cellphone? (0)

Anonymous Coward | more than 2 years ago | (#36942766)

What if the question becomes, can I use this to charge a dead (powered off) cell phone? It would be cool to have a little trickle charge so that say, over a month you would gain enough stored energy to make a 5 or 10 minute phone call. Basically just an emergency phone. Keep it somewhere, never turned on, always sucking up energy until it is needed.

Would this decrease reception, like we see in the iphone 4? I'm guessing it would cause a permanent "death grip" to have a radio wave catching "wall" right next to the transmitter.

Re:Can it power a cellphone? (2)

bragr (1612015) | more than 2 years ago | (#36942900)

I don't think you appreciate how minute the amount of energy you can recover from radio waves is. I doubt you could recover enough energy to cover the power used by devices when "off".

Re:Can it power a cellphone? (1)

alostpacket (1972110) | more than 2 years ago | (#36943040)

The article mentioned power in the milli and microwatt neighborhood. So I dont think there will be anything like that in the *near* future. However, the article actually seemed a bit sparse when it came explaining the practicle uses. It mentioned a temperature sensor, but what would that sensor do? Would it transmit data? Would it record it? Just "sensing" is mostly useless, no? Admittedly my understanding of this tech is about nil -- but it mentioned charging capacitors with these things. So I gather that's where the power would come from to transmit and/or write to storage. So my question was how much of this power can be stored? How long would the charge take? That would give us the info needed to imagine practical applications I would think.
 
I also find the concept that this is "green" power a bit off considering just printing these things may take more power than they could give back. It surely may have some great logistical, industrial, consumer or other applications, but I'm not sure it's "green" energy in the way most people think about it.

Big numbers (-1, Flamebait)

Anonymous Coward | more than 2 years ago | (#36942452)

"Experiments using the transmission bands from a TV station half a kilometre away from the test site have yielded hundreds of microwatts of power"

That could have sounded so much better in their press release if they have phrased it as "thousands of nanowatts" or even "millions of picowatts"

Amateurs........

Re:Big numbers (3, Interesting)

Fordiman (689627) | more than 2 years ago | (#36942592)

I wonder what the nominal ambient flux actually is (i.e., W/m^3), and how much of it they're actually capturing.

Re:Big numbers (3, Informative)

Omniscient Lurker (1504701) | more than 2 years ago | (#36942750)

Joke all you want. But a group in one of my engineering classes did this and we were received better than the group that did: .00something watts.

I guess marketing is easy.

Not a bad idea (0)

Anonymous Coward | more than 2 years ago | (#36942456)

It's not a bad idea since there is plenty of ambient radio waves (you can tap the strongest local radio station with nothing more than a coil of wire.)

Re:Not a bad idea (1)

houstonbofh (602064) | more than 2 years ago | (#36942518)

And as all these parasites degrade the actual signal, they will just crank up the power. Yep. Real green.

Re:Not a bad idea (1)

JorDan Clock (664877) | more than 2 years ago | (#36942608)

I think you fail to understand how radio waves work...

Re:Not a bad idea (1)

hedronist (233240) | more than 2 years ago | (#36942748)

I think you fail to understand how radio waves work...

When has lack of understanding ever stopped anyone on /. from commenting on anything?

Re:Not a bad idea (1)

houstonbofh (602064) | more than 2 years ago | (#36943240)

The power pulled out of the magic air space comes from somewhere, and is no longer going somewhere else. One power source will not make a difference. Just like one WiFi access point does not crowd out the spectrum. Have you looked around at how many networks you see? As more people use this, it will cast shadows behind it, shortening the range. The person providing service will have to crank up the power to overcome this, or provide serveice to less people.

I think you fail to understand how the law of conservation of energy works. http://en.wikipedia.org/wiki/Conservation_of_energy [wikipedia.org]

Re:Not a bad idea (1)

JorDan Clock (664877) | more than 2 years ago | (#36943390)

Alright, so we don't put these devices in walls and on ceilings? I still don't see how these will require the reaction you point out. If these are installed in tiny devices (Like RFID devices.) and carried in pockets or attached to keyfobs, they're going to have NO effect on the interception of radio signals unless you stick a few around your cellphone. These antennas aren't being used to paint walls, cover windows or wrap around your laptop. I think you're completely missing the point of this antenna.

Re:Not a bad idea (1)

Teancum (67324) | more than 2 years ago | (#36943800)

They're going to have NO effect on the interception of radio signals unless you stick a few around your cellphone.

I think you miss the point again. It does impact the reception of radio signals and this energy isn't "free". The proposal here is to be a leech on what somebody else is doing and it will impact the broadcaster.

To note a similar situation, high voltage power lines that connect power plants to major cities also "broadcast" E-M radiation around the towers coming from the transmission of the power itself. Sometimes enterprising individuals living close to these towers can "harness" this energy in several way, not the least of which is to run some wires around or near these towers and then "ground" the wires through some devices that utilize the energy. It is a nice way to tap into the power distribution system, but it also adds resistance to those power lines.

Don't do this, as utility companies do find out eventually (through several methods I won't go into here) as it is a power loss that does show up in terms of the energy being transmitted through the line. Radio broadcasters are really no different in that regard, but instead of expecting a certain amount of power at one end of a distribution line, they just fail to deliver their "product" (aka the programming) to some of their customers.

The reason why RFID devices are a little different is that the transmitter (aka "reader") is explicitly designed to emit some RF power in order to activate the RFID chips, which are in turn tuned to that specific frequency. It doesn't come cheap and there is a loss of power, but it certainly can't be called "green". BTW, these also have an impact on the interception of radio signals. Just one or two... yeah it doesn't make that much difference. Millions of them embedded into every shingle of your house and the houses of all of your neighbors (or some other common piece of construction)? It would have a huge impact. The issue here is how many of these devices would there be, and what would happen if terrestrial radio stations simply shut down because of this issue? It will happen if this becomes widespread.

Re:Not a bad idea (2)

timeOday (582209) | more than 2 years ago | (#36942740)

I'll give you a little dirt on solar panels too - they cast shadows, robbing whatever is in their shadow of its rightful electromagnetic energy! Same thing, different part of the spectrum.

Re:Not a bad idea (1)

houstonbofh (602064) | more than 2 years ago | (#36943248)

And a little dirt is no problem. A lot of dirt will cut the efficiency, so to get the same power you will need more panels.

Re:Not a bad idea (1)

Teancum (67324) | more than 2 years ago | (#36943834)

Light going onto solar panels may deprive plants from being able to receive that light. The issue here isn't just one of these devices or doing "experiments" with some ambient radio energy, but what happens when millions or billions of these devices are made and all tapping into that energy. That would be like covering all of the farmland completely with solar panels.... then how will food be grown? One or two of those things in strategic places or placed on rooftops that otherwise don't use that sunlight is one thing. Placing them in more valuable locations is something else completely.

The same goes for these devices where location is everything, and I don't see how even regulating how these are used can stop ordinary consumers from using them in places where their use will be a big deal.

dumb question (1)

Anonymous Coward | more than 2 years ago | (#36942468)

Maybe a dumb question, but do RF sinks like this act like 'black holes' for radio waves, affecting the reception quality within a kind-of 'event horizon' vicinity (maybe even requiring more power at the transmitter) ?

Re:dumb question (4, Informative)

houstonbofh (602064) | more than 2 years ago | (#36942528)

Yep. TANSTAAFL

Re:dumb question (3, Informative)

icebike (68054) | more than 2 years ago | (#36942554)

Maybe a dumb question, but do RF sinks like this act like 'black holes' for radio waves, affecting the reception quality within a kind-of 'event horizon' vicinity (maybe even requiring more power at the transmitter) ?

I don't think you can measure the effect at the transmitter of generating a wave that was otherwise destined to be absorbed by the surroundings or dissipated into space vs being detected on an antenna.

Perhaps a log floating on a pond into which you throw a rock blocks the ripple and creates a lee, and perhaps a lillypad in that lee bobs less, bit it makes no difference to the stone you throw unless your primary aim was to ripple that particular lillypad.

I suppose you could totally mask the intended receiver (TV aerial) of that TV signal by wrapping it in these paper antennas.
But the energy was already expended sending the wave. The transmitter won't need more power if that signal gets absorbed by the buildings or by the paper antenna. The antenna can only capture the energy already impinging upon it from the signal. It can't pull any more from the transmitter.

Re:dumb question (1)

Kral_Blbec (1201285) | more than 2 years ago | (#36942936)

Well put, but considering the dimensions and distances involved, it would be more like a needle sticking upright in the water shielding the lily pad than a log. The area shielding by the interference would be insignificant and only if it was in direct LOS.

Re:dumb question (1, Interesting)

bradgoodman (964302) | more than 2 years ago | (#36943046)

I keep equating it to the story about standing next to a transformer at an electrical substation - or high-power line with a coil, and trying to leach power from it. (I'm botching/simplifying the idea here)

One might argue "I'm not stealing power, because I'm just letting the EM field that the line/substation/coil is already sending through the air - go through my coil).

However, the field's emitter does have to work harder to generate the power which the consumer is using. If this wasn't the case, a power generator on one side of a transformer would be uneffected by (and see no load presented by) a load connected to the other coil on the "load" side of the transformer.

So - I would imagine it working the same here - the transmitter *would* have to "push harder" to accommodate people leaching power from it in this way.

Did I just make any sense? :(

Re:dumb question (1)

FLEB (312391) | more than 2 years ago | (#36943424)

I might be wrong (read: I'm talking out my ass here), but two big differences between tapping electrical-line power and tapping radio waves, in this respect, are that first, there is generally a lot more energy siphoned off the power lines, and second, the purpose of radio towers is to emit "x" amount of power with no expectation of ever seeing it again. OTOH, the power lines are being monitored on both ends, and the difference by EMF loss is compensated for by pumping more power into the system. While strictly speaking, too many of these antennas could cause a "shadow" that would block a radio signal, I can't imagine that in use they'd be placed right or be opaque enough to have an effect that required compensation.

Re:dumb question (1)

patniemeyer (444913) | more than 2 years ago | (#36943498)

A real engineer can speak to this better, but there is a big difference between the "near field" where you are actually coupling magnetically/capacitatively with the source and radiation which transmits energy over an arbitrary distance. I believe if you are stealing power by putting a big coil next to a power line you are essentially making half of a transformer and directly drawing power through it... whereas if you are at a greater distance all you can do is intercept radiated energy, which is already gone as far as the sender is concerned.

Re:dumb question (1)

sneakyimp (1161443) | more than 2 years ago | (#36942562)

Not a dumb question at all and yes I believe they do.

Re:dumb question (2)

labnet (457441) | more than 2 years ago | (#36943066)

Maybe a dumb question, but do RF sinks like this act like 'black holes' for radio waves, affecting the reception quality within a kind-of 'event horizon' vicinity (maybe even requiring more power at the transmitter) ?

Not Really.
EM comes in two main flavours
Near Field & Far Field.
In the near field you have a good chance of 'loading' the antenna, thus 'robbing' power but you need to be mighty close at high frequencies. eg. Within few cm at 1GHz.
In the far field, the EM wave propogates, and you as the reciever have no influence on the transmitter.
Do you rob other recievers around you? Yes, but the effect when compared to buildings, trees, the earth would negliable. A propogating wave will also fresnel around you. You would be like a speck dust to sunlight.

Wiress Power Harvesting (2)

cosm (1072588) | more than 2 years ago | (#36942490)

There are many cool projects out there where you can 'harvest' free wireless energy. I've read about people setting up receivers to pull energy (low wattage of course) from nearby microwave towers and the like. Don't have any sources, but I believe I've heard of some research teams or 'how to get free cheap power' sites/groups being harassed by the folks who owned the towers. All heresy, could not find any sources, anyone know anything else?

Also, and sorry for the cliche attribution, Tesla was a major proponent and researcher in this area, and wasn't a complete kook as revisionist history sometimes paints him to be. Margaret Cheney's "Tesla - A Man Out of Time" is a great read for a comprehensive history covering some of the early research in these areas.

A Very Bad Idea... (-1)

Anonymous Coward | more than 2 years ago | (#36942496)

Of course the problems with this are that by absorbing the radio broadcasts, you are in effect lowering
their propogation, creating lower coverage for their operation. This is most certainly not free energy
its widespread use would destroy the functionality of radio systems.

Of course its the kind of issue that everyone would consider to be someone elses problem (tm), but
in the end, it would be a big problem, and it is ahrd to see that the power being created would be enough
to warrant such issues.

Inkjet printers can print everything. (0)

MikeDaSpike (1196169) | more than 2 years ago | (#36942500)

But does it print Linux?

Re:Inkjet printers can print everything. (1)

houstonbofh (602064) | more than 2 years ago | (#36942552)

Yes, but the resulting product does not work as the power available to be harvested is not compatible with the GPL.

imagine a beowulf 3d printer cluster (1)

decora (1710862) | more than 2 years ago | (#36943154)

... and petrification

Re:imagine a beowulf 3d printer cluster (1)

tloh (451585) | more than 2 years ago | (#36943700)

Ah, nostalgia! None of the younger slashdoters have any appreciation for the old jokes anymore. Curse me for having commented here, otherwise, I'd mod you for 'funny".

IANARS, but... (2)

argStyopa (232550) | more than 2 years ago | (#36942530)

I am not a radio scientist, but ... if the new tech pulls power out of the radio signal, isn't this going to a) degrade the signal for anyone 'downstream' of the absorber, and/or force broadcasters to pump MORE power out to maintain signal generally?

Re:IANARS, but... (1)

Anonymous Coward | more than 2 years ago | (#36942612)

Absolutely.

This energy is only as green as the energy source to the radio tower. Furthermore, radio signals are used because most materials are fairly transparent to radio waves. If people start making radio-opaque stuff to steal energy out of the air, it will degrade our shared infrastructure.

Fortunately, it should be easy to find who has radio-opaque energy theft equipment. Just look for its shadow.

Re:IANARS, but... (0)

Anonymous Coward | more than 2 years ago | (#36942630)

Only if it's directional or the device itself is large / has radio reflectors to increase wattage draw. Absorbing the radio waves for energy is no different effect then listening to it.

Of course, generally speaking, these devices probably can be set to avoid certain frequencies (not all ambient radio waves are generated by humans or on purpose) if they was large enough to interfere. Kinda moot though since it isn't even the target market, more for small devices where a battery is too limiting as the possible current you can draw out is simply low even compared to solar.

Re:IANARS, but... (5, Informative)

Tacvek (948259) | more than 2 years ago | (#36942660)

It will degrade the signal of downstream recipients. So does absolutely every radio receiver, with no exceptions.
However, please consider that the only downstream recipient may well be the earth or space, considering that the path between a transmitter and receiver often does not pass particularly close to another receiver. How much one of these would impact the downstream signal quality anyway depends on just how much power this is extracting, and just how weak the signal would have been at the downstream receiver without this being present.

Also keep in mind that radio waves can be rather fickle. Placing these devices in certain locations may actually increase the received signal strength downstream, perhaps by absorbing an interference source, or by attenuating a secondary path of the signal which would have interfered with the primary signal.

Re:IANARS, but... (4, Informative)

rubycodez (864176) | more than 2 years ago | (#36942946)

more broadly, so does every conductor in an RF field. We'd better outlaw file cabinets, metal kitchen utensils, pocket change and reinforced concrete buildings.

Re:IANARS, but... (1)

whiteboy86 (1930018) | more than 2 years ago | (#36943092)

Tame the Vodafone tower of excessive wattage nearby, send the juice home, do not let them irradiate you!

Progress (0)

Anonymous Coward | more than 2 years ago | (#36942584)

Now your RFID tags can broadcast 24x7 and can be picked up and logged by Google Street View cars as they drive down your road.

FCC says? (4, Interesting)

HTH NE1 (675604) | more than 2 years ago | (#36942600)

Which reduces the quality of the radio signal for anyone downwave from the power harvesting site. It effectively steals power from the transmitter intended to provide service to those more distant than you from the transmitter.

Permissible is interception for purpose of reception of the signal, such as a crystal radio, at a small scale. Not permissible is powering your lights, robots, or anything else that does not simply turn the signal back into its intended form.

It may be permissible to leech power from a WiFi signal in order to power a device that will use the data in the stream if you could be sure you're stealing power from signals intended for you and no one else.

But AFAIK the rules are to protect man-made signals, unless the scientific community have petitioned to protect their ability to study background radiation by preventing the same harvesting of power from natural radio sources, else they'll have to do their studies elsewhere.

Re:FCC says? (1)

JanneM (7445) | more than 2 years ago | (#36942834)

So⦠What about shielding then? Having RF shielding to protect electronics (or using building materials that shield an entire room or house for that matter) also degrades the downstream signal, without using the data in any way.

I could be wrong Ââ" I frequently am â" but I doubt your argument would really hold in practice.

Re:FCC says? (2)

JanneM (7445) | more than 2 years ago | (#36942858)

"Soæ "

I'm sure slashdot will support something beyond 7-bit ascii any century now...

Re:FCC says? (0)

wholesale1 (2418238) | more than 2 years ago | (#36942886)

P90x is an extremely intense program.Sheer will and determination may get you to the finish line,but to achieve the best results,you’ve got to have the proper quality and quantity of nutrition.We make these supplements optional,so you have a choice.But know that P90x supplements were designed for this program and will supply your body with the necessary nutrients to give you added strength energy,and stamina for each workout. As you may notice from the math on the following pages,P90x ia not bulit around adaily “calorie deficit” for weight loss like the general Beachbody plans found in Power 90,Kathy Smits’s Project :You!Type 2,and Slimin 6.It’s important that you understand why ,so you have the right training mentality with this program ,with the right expectations. http://www.dvd4wholesale.com/exercise-fitness-dvds/34-p90x-textrme-home-fitness-13-discs-set-wholesale.html [dvd4wholesale.com] http://www.dvd4wholesale.com/ [dvd4wholesale.com]

Re:FCC says? (0)

Anonymous Coward | more than 2 years ago | (#36942978)

The point of this type of technology isn't to harvest "large" amounts of power. Typically energy harvesting devices are used to provide power to remote devices to avoid using batteries. For example: http://www.intelligent-systems.info/bridge.htm

Re:FCC says? (1, Interesting)

Kral_Blbec (1201285) | more than 2 years ago | (#36943010)

Incorrect. It doesn't reduce the signal quality for anyone downwave from the transmitter. It only reduces signal quality for those in the direct path of travel in a line intersecting the transmitter and this power harvesting antenna. It can only interact with waves that travel directly through it already. It doesn't alter the path of travel of nearby waves to suck them in. In this it is just like any other receiving device, meaning it wouldn't effect signal quality any more than having an equal number of radios/TVs.
Considering the height of radio/TV towers, the direct path of travel is mostly going to be into the ground anyway. The energy this would pick up would be wasted anyway.

Re:FCC says? (1)

evilviper (135110) | more than 2 years ago | (#36943698)

Considering the height of radio/TV towers, the direct path of travel is mostly going to be into the ground anyway. The energy this would pick up would be wasted anyway.

This is only true if you're fairly close to the broadcasting antenna. Thanks to the curvature of the earth, what's on the top of a mountain, 50 miles away, is now at ground-level... Any yes, at that range your neighbors on the opposite side are picking up TV signals barely above ground level where you are, if not picking-up on signals that are actually reflecting off the ground. You often see high-gain antennas angled downward for these reasons, and there certainly is some opportunity to degrade signal strength for your neighbors.

Re:FCC says? (4, Insightful)

labnet (457441) | more than 2 years ago | (#36943082)

Which reduces the quality of the radio signal for anyone downwave from the power harvesting site. It effectively steals power from the transmitter intended to provide service to those more distant than you from the transmitter.

Permissible is interception for purpose of reception of the signal, such as a crystal radio, at a small scale. Not permissible is powering your lights, robots, or anything else that does not simply turn the signal back into its intended form.

It may be permissible to leech power from a WiFi signal in order to power a device that will use the data in the stream if you could be sure you're stealing power from signals intended for you and no one else.

But AFAIK the rules are to protect man-made signals, unless the scientific community have petitioned to protect their ability to study background radiation by preventing the same harvesting of power from natural radio sources, else they'll have to do their studies elsewhere.

A little bit of knowledge is a dangerous thing!

Re:FCC says? (0)

Anonymous Coward | more than 2 years ago | (#36943116)

See above comment

Re:FCC says? (0)

Anonymous Coward | more than 2 years ago | (#36943286)

I can't believe anyone modded this up.

We're talking about teeny tiny amounts of power. This is for powering devices that require teeny amounts of energy without batteries or a normal power source. You'd never even come close to being able to power the smallest lightbulb with the amount of power you could harvest from a radio transmission.

If you think that broadcasters have some strange inherent right to their signals being propagated, and not blocked, then you might want to start outlawing all metals.

How much time before this is illegal? (1)

kandresen (712861) | more than 2 years ago | (#36942602)

I remember it was demonstrated that people living close to the grid could get free energy simply by using a coil.

It did not take long though until this became prohibited as it actually did tap the energy from the cables. It even resulted being possible to detect someone was tapping the power.

So here we are again, this time with power from radio waves. How much interference does this cost if we add to the scale? will the radio stations and wireless access points get reduced range by this? If so, don't be surprised that this technology too will be deemed illegal.

Re:How much time before this is illegal? (0)

Anonymous Coward | more than 2 years ago | (#36942676)

I remember that the Mythbusters tested it to see if it was possible. They had to get information from both the state and the power company to test it. However, they barely got any energy from the lines despite the rather large rig and amount of wire. So, I wonder what this would really be good for powering.

Re:How much time before this is illegal? (1)

Kral_Blbec (1201285) | more than 2 years ago | (#36943038)

Not to mention there is a difference between a shield 100 feet from a source and 3 miles. Just like a shadow, the affected area is a matter of size and distance. A piece of paper miles miles from a source isn't going to have much of shadow.

Re:How much time before this is illegal? (0)

Anonymous Coward | more than 2 years ago | (#36942914)

Free energy?

No, the energy involved cost money to produce.

It's stolen energy, the same as if you put a copper line right in the tap.

Re:How much time before this is illegal? (1)

UnknownSoldier (67820) | more than 2 years ago | (#36943084)

> I remember it was demonstrated that people living close to the grid could get free energy simply by using a coil.
> It did not take long though until this became prohibited as it actually did tap the energy from the cables. It even resulted being possible to detect someone was tapping the power.

That's actually pretty cool if true. You have any links or google-fu terms to use so we can find out more about this?

Cheers

Re:How much time before this is illegal? (0)

Anonymous Coward | more than 2 years ago | (#36943190)

Yeah, you could look up electricity theft, arrest, jail.

Because that's where you are going to go if you try this.

Re:How much time before this is illegal? (1)

Eil (82413) | more than 2 years ago | (#36943396)

I went researching this one time and so far as I can tell, it's a almost a complete urban legend. The version that I heard was that some guy lived directly under some high-voltage power lines. Huge kilovolt transmission lines with gigantic steel towers and a dozen or more conductors. Anyway, the story went that he built a large copper coil in his attic, and managed to leech enough power to light his whole house. The electric company eventually notices that his electricity bill dropped by 90%, the police get involved, and so on.

I can find nothing that says anyone has ever tried this, but perhaps more surprisingly, I haven't seen anyone with the theoretical knowledge to work out the equations to prove or disprove the concept of leeching electricity from the ground. The only two concrete things I ever found were:

A mythbusters episode where Adam and Jamie try to duplicate the myth. They fail horribly, but their test setup was really quite awful too. (And the fact that they consulted with ZERO experts on the topic. It's like me busting the myth that a man can set foot on the moon because I can't do it.)

A guy who did an art installation by literally planting a few hundred fluorescent tube light bulbs into the ground under a transmission power line. One end in the dirt, one end in the air. It worked quite well. The bulbs light dimly at dusk. (If you find any photos, note that they exaggerate the effect via long exposure.) I think the tubes' phosphor coating is reacting to the RF field generated by the power lines. I highly doubt that there is any current whatsoever flowing from the upper tips of the tubes to the lower tips.

So, with my limited knowledge of electricity, my suspicion is that it may be possible to capture very small amounts of energy from being directly underneath a power line. But you're not going to be able to do it covertly and get anything approaching a usable amount.

Re:How much time before this is illegal? (1)

kandresen (712861) | more than 2 years ago | (#36943466)

This was from about 1980-85 so it was way before Internet...
It was demonstrated with a 60w light bulb, sure it was not as bright as it would have been if connected to the cord, but the coil was for sure no more than a kilo, mostly copper. The light bulb was connected to the coil and it was demonstrated holding it up in the air, I were allowed to hold it up myself. The closer we got by the power lines the brighter the light.

The method is mentioned somewhat here: http://en.wikipedia.org/wiki/Inductor [wikipedia.org]

The one we used looked more like the middle one in the upper picture on that page, but it was bigger, had a finer copper wire, and it was twisted around the ring much more than that one.

The essential point is to get the coil in the same frequency as the your power grid. The one who made the one I saw was a electrician by profession, and knew the math behind it well. Note also that it was done in Europe with 240 volt power, but I believe the grid we was close to had an even greater voltage(?)

This guy claims he got 4kwh from what to me sounds like the same mechanism, though he was an amateur originally believing he got power from the aether... : http://www.pureenergysystems.com/news/exclusive/wireless_transformer/ [pureenergysystems.com]

The article is most certainly correct that it is prohibitively expensive if living even a few hundred meters from the power lines. But the electrician who demonstrated it was also the one stating the company could notice the power drop on the line when used extensively, and would then investigate it, find you, and prosecute you.

Re:How much time before this is illegal? (0)

Anonymous Coward | more than 2 years ago | (#36943820)

You could read up on how tranformers work or possible just Faraday's law of induction [wikipedia.org] .

This part from the wikipeda page pretty much sums it up:

When the electric current in a loop of wire changes, the changing current creates a changing magnetic field. A second wire in reach of this magnetic field will experience this change in magnetic field as a change in its coupled magnetic flux, a d B / d t. Therefore, an electromotive force is set up in the second loop called the induced EMF or transformer EMF. If the two ends of this loop are connected through an electrical load, current will flow.

So, the current flowing through the power line will greate a magnetic field that can be induced into a conductor that is placed parallel to the power line.
To increase the voltage you can either place the conductor closer to the power line or make the conductor longer.

Re:How much time before this is illegal? (1)

Eil (82413) | more than 2 years ago | (#36943258)

So here we are again, this time with power from radio waves. How much interference does this cost if we add to the scale?

None. No interference is generated by a properly-functioning receiver.

will the radio stations and wireless access points get reduced range by this?

Every antenna, tree, power line, flag pole, chain-link fence, and filing cabinet within range of a transmitter is already shunting a small portion of that transmitter's power to ground. The rest of the signal which is unhindered by any natural or man-made objects simply skips all the excitement and either goes straight into the ground or is weakened to nothing in the atmosphere.

I'm not going to tell you why this is, but I am going to give you the opportunity to experiment for yourself:

1. Locate the nearest wifi access point and associate two laptops with it. These should have built-in wifi and have similar screen sizes, as the antennas are located on either side of the screen.
2. Put the first laptop on a table, with the screen facing the access point
3. Put the second laptop back-to-back with the first, with the screen facing away from the access point.
4. Did the second laptop lose its wifi signal? Why not?

A whole milliwatt!!! (1)

Anonymous Coward | more than 2 years ago | (#36942614)

They think they can generate a whole milliwatt! So if the system ran non-stop for 10 years, it could produce over a penny's worth of electricity!

Re:A whole milliwatt!!! (0)

Anonymous Coward | more than 2 years ago | (#36942792)

you can run a small 32-bit cpu off a milliwatt.

Re:A whole milliwatt!!! (1)

rubycodez (864176) | more than 2 years ago | (#36942906)

really, what model? I"ve only seen tens of milliwatt chips.

Re:A whole milliwatt!!! (1)

JanneM (7445) | more than 2 years ago | (#36942876)

Think body embedded sensors for instance. They use a tiny amount of power; getting at them for battery replacement is very invasive; and active recharge though an external coil or similar requires external equipment and having users remember to do so would be a common point of failure.

Re:A whole milliwatt!!! (0)

Anonymous Coward | more than 2 years ago | (#36943364)

I'd pay a dollar to see that.

Can we chip our wives now? (1)

elucido (870205) | more than 2 years ago | (#36942626)

It's only a matter of time before the technology is ready.

Re:Can we chip our wives now? (0)

Anonymous Coward | more than 2 years ago | (#36942780)

How many wives do you have? Do they keep getting lost or is it that you simply can't keep track of them?

Re:Can we chip our wives now? (0)

Anonymous Coward | more than 2 years ago | (#36943170)

Only in Stepford.

dumb-ass obvious water-is-wet announcement (1)

rubycodez (864176) | more than 2 years ago | (#36942930)

Gee, an antenna converts radio waves to AC. This phenomenon has been quite well known since the 19th century. For something a little more modern, and a whole lot better than a fucking printed antenna, you can use a metal fractal antenna for wide band coverage.

Re:dumb-ass obvious water-is-wet announcement (1)

DavidRawling (864446) | more than 2 years ago | (#36943212)

Did you miss the bit in the summary about how this is being done using an antenna printed on paper, using an inkjet to provide a very low cost of production? The 19th century I've read about didn't have inkjet printers or the nano-tech metallic ink to create them.

Do you reject any other advances in approach that "have been done before differently"? Drive a steam powered car (yes, I know they exist), because "converting liquid fuel to motion by burning it to create energy has been quite well known since the 18th century"?

Re:dumb-ass obvious water-is-wet announcement (1)

drinkypoo (153816) | more than 2 years ago | (#36943542)

Or maybe instead of pooh-poohing this you could suggest printing a fractal antenna... booyeah.

Of course I didn't RTFA, they may have done so already.

Beamed power! It's Magic! (0)

Anonymous Coward | more than 2 years ago | (#36943062)

Inc.!

Re:Beamed power! It's Magic! (0)

Anonymous Coward | more than 2 years ago | (#36943096)

Oops! I mean, it's Waldo world!

nig6A (-1)

Anonymous Coward | more than 2 years ago | (#36943074)

a form of pollution? (0)

Anonymous Coward | more than 2 years ago | (#36943122)

First sentence in TFA:

Radio wave propagation may be a form of pollution

And that's where I stopped reading.

Re:a form of pollution? (1)

deprecated (86120) | more than 2 years ago | (#36943394)

Me too. My BS detector went off the scale.

Re:a form of pollution? (1)

tloh (451585) | more than 2 years ago | (#36943674)

Oh, come on guys! EMI much? Not all pollution is the biological kind! Ask any (radio) astronomer. http://xkcd.com/654/ [xkcd.com]

Area of a Sphere (1)

kd3bj (733314) | more than 2 years ago | (#36943184)

Power radiated from an antenna propagates outward in a mostly spherical distribution (not accounting for directivity, ducting, etc..) and a sphere has an area of 4 pi r^2. The amount of power received is proportional to the area of the receiving antenna. You will find, if you do the simple math, that r^2 get big real fast and that any practical receiving antenna at any significant distance subtends only a tiny fraction of that sphere's total area and thus only receives a tiny fraction of the radiated power.

They've re-invented the Checkpoint tag (1)

Animats (122034) | more than 2 years ago | (#36943228)

They've re-invented an older model Checkpoint anti-theft tag, the square "sticker" model 410 with an antenna printed in conductive ink and an IC at the center. The Checkpoint tag IC is rather dumb, but then the whole tag costs about $0.05.

spon6e (-1)

Anonymous Coward | more than 2 years ago | (#36943280)

ver>y distracting to

Great News! (1)

paleo2002 (1079697) | more than 2 years ago | (#36943340)

Scientists have finally found a purpose for AM radio!

Apple mac books: 280- 520 USD Iphone 4: 260 USD (1)

addtostock3 (2113030) | more than 2 years ago | (#36943428)

Apple mac books: 280- 520 USD Iphone 4: 260 USD Ipad 2 64gb wifi 3G : 330 USD New Ipod touch 64gb: 120 USD Dell Alienware M17x: 700 USD Dell Alienware M15x: 500 USD MacBook Pro MC024 LL/A 17-inch 2.66GHz Intel Core i7: 510 USD MacBook Pro MC373 LL/A15.4-inch 2.66GHz Intel Core i7: 485 USD BlackBerry Pearl 3G 9105: 350 USD Nikon F 6 SLR camera - 35mm: 685 USD Nikon D3000 (with 18mm-55mm and 55mm-200mm lens): 315 USD Nikon D3X : 985 USD Canon EOS 5D Mark: 565 USD Playstation 3 PS3 Metal Gear Solid 4 80GB Bund: 220 USD Free shipping , P A Y P A L accepted! Fast and door to door delivery! If necessary, please http://www.goelectronstore.com/ [goelectronstore.com]

Lowsy ideas... (1)

evilviper (135110) | more than 2 years ago | (#36943714)

The scavenging device could piggy-back solar energy panels so that, when the system stops generating power at sundown, the wireless energy could be used overnight to increase the battery charge or to prevent power leakage. The devices would also be useful in remote areas where an outage of a traditional power source could be flagged by sending a distress signal from an antenna-powered unit.

These are incredibly stupid ideas...

If you're using even the tiniest of solar panels for power, the extra power from this thing wont even register. Maybe if you're using it as a backup for a tiny thermocouple it'll help, but that's about the only other power source in the same ballpark...

If you've got a "power source" and want to send a distress signal when it goes out, you store up a bit of power from your main source, and can completely forego this antenna. The derission of batteries is nonsense (give me one NiMH cell...), but even if you buy the premise, one of those mentioned "ultracapacitors" charged from the grid would be vastly more suitable than using this power antenna at all...

Load More Comments
Slashdot Account

Need an Account?

Forgot your password?

Don't worry, we never post anything without your permission.

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>
Create a Slashdot Account

Loading...