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Power Technology

Radio Energy Harvested With Inkjet-Printed Antenna 164

Posted by samzenpus
from the catching-the-waves dept.
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."
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Radio Energy Harvested With Inkjet-Printed Antenna

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  • by Anonymous Coward on Sunday July 31, 2011 @08:08PM (#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.

    • by icebike (68054) on Sunday July 31, 2011 @08:20PM (#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.

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

        • by Ohrion (814105)
          Stop using arguments against useless buzzwords!!!
        • by EdIII (1114411)

          I think you mean that marketing has polluted the word so thoroughly that it is hard to take it seriously. In a way it has been gang raped and never truly recovered.

          However, the intended meaning of "green" to scientists and intellectuals (I guess) is that the technology results in a net loss of expended energy somewhere. It may be generating energy, or just being more efficient at an unclean process, therefore making it "green" because it is not as bad as the alternative.

          Calling Flex Fuel "green" when it r

        • Maybe the circuits were printed with green coloured ink?
        • is completely and utterly vague, and has become like 'fascist' or 'capitalist' or 'communist', a word without any actual, real meaning.

          *Glances at Canada's Green Party, which is apparently debating the benefits of homeopathy and recently made an anti-wifi declaration that would also ban the sun.*

          Clearest definition I see from here is "crazy and stupid". Maybe it's vague south of the border?

      • by AmiMoJo (196126)

        There were articles in radio magazines decades ago about people living near transmitters harvesting free energy, and the broadcasters maintaining that it was illegal to do so and would interfere with reception. I'm no expert but it seems that if you are converting radio waves into electricity then you are removing some energy from them, meaning that there is less energy available for others to receive. How significant that is I don't know... Say everyone started using this technique, would it affect recepti

        • by Pieroxy (222434)

          Unless your device is placed in between the emitter and someone wanting to actually receive them, I can see no possible interference.

          • by SEWilco (27983)
            So I won't be able to watch TV, listen to the radio, nor use my cellphone when the warehouse next door is filled with RFID tags.

            This also is only "everlasting" and "green" for as long as the nuclear power plants are feeding the broadcasters with cheap energy. Unless the antennas can generate enough energy from the cosmic microwave background radiation.

            • by Pieroxy (222434)

              This also is only "everlasting" and "green" for as long as the nuclear power plants are feeding the broadcasters with cheap energy. Unless the antennas can generate enough energy from the cosmic microwave background radiation.

              Today, this energy is wasted 100%. If we can harvest a little out of it, it's a bonus.

      • Actually, these devices do put a load on the emitting antenna, and (if done on a sufficiently large scale) the broadcasters are not amused
    • by fuzzyfuzzyfungus (1223518) on Sunday July 31, 2011 @08:33PM (#36942514) Journal

      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.

    • 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.

      • by X0563511 (793323)

        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)

      • by Divebus (860563)

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

    • by mcrbids (148650)

      99.9998% of the power emitted by my pocket cell phone is wasted. Only the minute fraction of those waves that happen to coincide with the line between myself and the cell tower are actually converted into anything useful. Sadly, the 99.998% ratio is probably optimistic, it's likely to be considerably worse than that!

      So here we are, covering the Earth with radio-emitting devices by the billions, (with a "B") with emissions ranging from a few milliwatts per device up into the millions. Thanks to the inverse-s

  • by YesIAmAScript (886271) on Sunday July 31, 2011 @08:09PM (#36942394)

    It's called a crystal radio.

    A diode does it too.

    • by fuzzyfuzzyfungus (1223518) on Sunday July 31, 2011 @08:41PM (#36942594) Journal

      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...

    • True - I used to have a crystal set that I'd occasionally hook up to a digital analogue clock and it would run fine throughout the day and up until one of the more local stations went off the air for the night.

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

    • by DrBuzzo (913503)
      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.
    • 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 gath

      • I think that the "green" can be understood in comparison to the alternatives. If you don't power these things with radio waves, you have to use something like either batteries or a proper power installation connected to the mains. Either one of those things is likely to use much more resources. However, the fact you can do these installations without batteries will likely lead to many more of them being done. That will only be "green" if each installation saves much more energy than is used in it's prod
      • by grumbel (592662)

        It mentioned a temperature sensor, but what would that sensor do? Would it transmit data?

        Measure temperature and record it I would assume. If that stuff would get cheap enough you put stickers with it on all food and find out if there after was a lapse in the cooling chain. Reading that info out would then be done with regular RFID gear I assume, as I doubt there is enough power in the air for retransmission.

        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.

        The "green" part is that you might be able to use it in places where you otherwise would need to use a replaceable battery and since it last forever, that can be quite a saving.

      • by GooberToo (74388)

        There are a number of wireless sensor network technologies whereby the periodically wake a CPU, take a reading, and record it. When full, they then transmit their sensor values to a centralized hub (typically larger and/or solar powered + these) or mesh network. These in turn tend to use this type of technology to steady recharge their batteries. The amount of power recovered is small, but so is the device's power demands. In many cases, people report modest battery life extensions (say something like 20%-3

  • by cosm (1072588) <thecosm3@gmail . c om> on Sunday July 31, 2011 @08:29PM (#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.
  • by argStyopa (232550) on Sunday July 31, 2011 @08:35PM (#36942530) Journal

    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... (Score:5, Informative)

      by Tacvek (948259) on Sunday July 31, 2011 @08:50PM (#36942660) Journal

      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... (Score:5, Informative)

        by rubycodez (864176) on Sunday July 31, 2011 @09:46PM (#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.
        • You're doing fine. But you'll have to stop when you get to handguns. There's an idea, ban all metal objects except handguns, and then handguns will be incredibly easy to detect.
          • by rubycodez (864176)
            why not just have required open carry?

            maybe we could keep night sights charged with this technology
        • My understanding was that your average conductive thingamajig only absorbed tiny amounts of energy from a passing wave as the electrons shuffled about resulting in a tiny bit of heat, while something designed to take the signal and convert it into power (or even just signal) sucks far more energy out of the signal.

    • Tame the Vodafone tower of excessive wattage nearby, send the juice home, do not let them irradiate you!
  • FCC says? (Score:5, Interesting)

    by HTH NE1 (675604) on Sunday July 31, 2011 @08:42PM (#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.

    • by JanneM (7445)

      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.

      • by JanneM (7445)

        "Soæ "

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

    • Re: (Score:2, Interesting)

      by Kral_Blbec (1201285)
      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 r
      • by evilviper (135110)

        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

    • Re:FCC says? (Score:5, Insightful)

      by labnet (457441) on Sunday July 31, 2011 @10:10PM (#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!

    • by wkcole (644783)
      You speak of rules and permissibility, but you fail to cite where those rules are. I've looked at the FCC regs and can't find what you claim exists. Cite please?
    • TFA says they are generating "hundreds of microwatts of power." Nobody is going to be powering their lights or robots off of this tiny trickle of electrons.

  • 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 sur

    • > 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

      • by Eil (82413)

        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

      • by kandresen (712861)

        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 w

    • by Eil (82413)

      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

  • 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.
    • 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

      • by rubycodez (864176)
        in the 19th century they had pencils that could put graphite on paper, you can draw your very own antenna (or circuit conductors) for less than ten cents of materials. You can make your own conductive ink too. These things have been part of fun science experiments for kids for decades, I did them 35 years ago. Steam engines are thousands of years old, by the way.
        • by rubycodez (864176)
          in the 19th century, they also had tin foil that could be cut out and adhered to a sheet of paper or fabric or wood or plaster wall......god damn, this article's "invention" is so fucking banal
    • by drinkypoo (153816)

      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.

      • by rubycodez (864176)
        Metal antenna can be made cheaper than their silly exotic inks, and are far more durable. For a few bucks, one can make a homemade conductive ink with graphite, fixer and solvent, that's an old kid's experiment from decades ago, can brush that stuff on clothing or paper or a wall and use as antenna or as wires to connect circuit elements. a bit more versatile than this article's ivory tower dweebs and their complicated way of making something less useful, more expensive, less durable....I give this ten
        • by drinkypoo (153816)

          Heh, reprap. FLEX!

          I agree with you today, but this is an important step. We can print circuits, now we can print antennas. How long before your cereal box spies on you?

  • 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.

  • Scientists have finally found a purpose for AM radio!
  • 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 th

  • If you embed 1,000 of these milliWatt antennas in the floor of your house you get 1 W. With a large house you might even be able to get enough energy to power something or charge a battery. You don't degrade signal quality for anybody if you live at the first floor. Governments could even support this method of harvesting wasted energy, especially if the decide to tax it ;-) I wonder what's the power used by a typical radio/TV station. We can't collectively collect more than they collectively emit.
    • by Issarlk (1429361)
      Assuming that 1000 antennas stacked together produce 1000x the output of one antenna. I doubt it and imagine that beyond a certain number you have harvested all there is and hit serious diminishing return.
  • by jklovanc (1603149) on Monday August 01, 2011 @04:27AM (#36944558)

    Why do so many of recent "technology breakthrough" articles follow the same pattern.
    1. Take an experiment that shows some minor interesting results (in this case the ability to pull microwatts from radio waves)
    2. Extrapolate it into unproven areas (in this case the ability to pull a milliwatt)
    3. Combine it with another theoretical, non commercial technology like superconducting motors, lithium air batteries or in this case super-capacitors.
    4. call it a breakthrough

    In my mind it is not a breakthrough until the technology is scaleable and commercially viable. Until then it is interesting science and only that.

  • Is there a place I can buy inkjet cartridges and print my own circuits?
  • Could this harm MIMO (multiple-input, multiple-output) communication systems which rely on multipath transmission?

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