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Radio Energy Harvested With Inkjet-Printed Antenna
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."
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.
It's called a crystal radio.
A diode does it too.
http://lkml.org/lkml/2005/8/20/95
It would be cool to power a cellphone with this. I don't mean transmit, silly, but the receive side, while otherwise asleep.
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) ?
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.
'We are trying to prove ourselves wrong as quickly as possible, because only in that way can we find progress.' RPF
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And as all these parasites degrade the actual signal, they will just crank up the power. Yep. Real green.
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?
-Styopa
Yes, but the resulting product does not work as the power available to be harvested is not compatible with the GPL.
I wonder what the nominal ambient flux actually is (i.e., W/m^3), and how much of it they're actually capturing.
110100 1101000 1101000 1100110 0 1101111 1101000 1100011 1
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.
Oh, say does that Star-Spangled Banner entwine / The myrtle of Venus with Bacchus's vine?
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.
I think you fail to understand how radio waves work...
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!
It's only a matter of time before the technology is ready.
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.
I think you fail to understand how radio waves work...
When has lack of understanding ever stopped anyone on /. from commenting on anything?
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.
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.
is completely and utterly vague, and has become like 'fascist' or 'capitalist' or 'communist', a word without any actual, real meaning.
... and petrification
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 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.
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
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.
Scientists have finally found a purpose for AM radio!
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.
Me too. My BS detector went off the scale.
Oh, come on guys! EMI much? Not all pollution is the biological kind! Ask any (radio) astronomer. http://xkcd.com/654/
Stay sentient. Don't drink bad milk.
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...
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
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.
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.
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.
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.
there is so many many ways they could make a Prius all electric.. like this for example.. your car gets radio stations.. use it.. your car travels down the highway but you only get power from breaking? lame.. what has become of wind turbines that generate energy? why not attach two to the front end of a Prius and have unlimited power coming in if your stopping or moving power is regenerating.
Is there a place I can buy inkjet cartridges and print my own circuits?
You say things that offend me and I can deal with it. Can you?
It costs an negligible amount of money to produce, and a radio transmitter is already throwing away energy by transmitting in all directions, irrespective of there being a receiver in that direction or not. Am I going to start paying for the radio wave energy being absorbed by my body, too?
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.
That that is is that that that that is not is not.
Could this harm MIMO (multiple-input, multiple-output) communication systems which rely on multipath transmission?
Or, ya know, these devices will just soak up all the stuff that DIDN'T go to a receiver. I think you're really overestimating the impact. We're talking about a keyfob size device that when not being actively used, it is recharging via radio waves that are otherwise "lost."