https://en.m.wikipedia.org/wiki/Rectenna
What they’ve done here is use the very old existing rectenna technology and new types of nanoscale rectenna arrays to capture very low energy radio waves without an external antenna. We’re taking -20 dBm or 10 μW.
In the end, I welcome any rectenna advances because if we ever build an efficient optical rectenna it’ll blow photovoltaics out of the water by efficiency. Optical rectennas are like fusion power in just how revolutionary they would be to our energy economy.
Dang that’s actually a super interesting concept. Thanks for the wikipedia link!
Agreed, this is the future Nikola Tesla wanted, and it’s not some wild eyed crack pottery but what he was actually working on in Colorado.
Once its implementation is feasible and it can extract the waste energy efficiently, this innovation will enable new types of devices and uses that will be critical for commercial, scientific, medical and personal.
Sounds like it’s still more theoretical than realized, at this point. Still, I can’t help thinking this would be really cool for something like a watch or hearing aids.
Still, I can’t help thinking this would be really cool for something like a watch
Watches have been solved. You put a solar panel in the watch face. No need for anything more.
Smart watches use too much energy to do any remote powering with at all, short of qi charging/other near-touching power distribution.
It will be used for ads…as usual…
it’s called an antenna. That’s its job.
Isn’t that one of Nikola Tesla’s inventions? Free electricity through the air?
Nah, that was just blasting a microwave beam at a collector. It would work and be meh on efficiency, but also bake everything between the two points…neat innovative theory, bad idea. Tesla was a smart dude, but his bad ideas were left ignored for a reason.
That’s not right… He was trying to achieve wireless power through Earth resonance. Which AFAIK is pretty much now completely debunked as never going to work … but it tracks with Tesla’s world view.
It’s kind of crazy how much you can build without a complete understanding… There’s probably stuff we think we understand now that we really don’t and other stuff left to discover.
how much you can build without a complete understanding
We’ve never actually never had one. I’d have to check the timelines but Tesla was almost certainly working on a functional, but inaccurate atomic model (Bohr). Medicine is actually a great example of all this. We are so used to just kind of knowing “there’s a bad bug or bad gene that’s making me sick”. Like you may not know the details, but you’ve got some loose concept a bunch of cells in your body are pissed off. For the vast, vasssssssst history of medicine, it was all empirical, and the thing is, it kind of worked… sometimes.
My favorite example of “knowing without fully understanding” is Mendel and his peas. If you do a 4x4 punnet square (that gene cross thing), and look at the frequency of co-inheritance, you can track how far genes are from on another (because the further they are, the more likely there will be a swap during the shuffle). Thing is… because DNA is an integer thing (no such thing as ‘half a base pair’) it works DOWN TO THE SINGLE BASE PAIR. Mendel was accurately counting the number of freaking base pairs separating genes without knowing what a base pair, or indeed even really a molecule, was.
Tesla would have lived to see some absolutely nutty stuff in physics. Boltzman, Einstein with relativity, it must have seemed like pure madness at the time.
So yeah, we discover new and interesting stuff all the time. I personally think that some of the weird quantum stuff is going seem as rote in the future as germs do to us now. As in, the same way any lay-person shoved into a time machine would at least be able to give the basics to a medieval European, someone from the future would be like “well I don’t remember much about quantum tunneling, but…”.
And that’s all before getting into some of the bizarre things going on in math itself. Be careful if you look into that stuff though, it’s easy to fall into the “Terrance Howard” style rabbit hole. Suffice to say there is some really interesting and unexpected implications we’re discovering, but if you don’t have a solid grasp of theory, it is easy to be led astray but sources that want to gloss over details to talk about a conclusion that isn’t actually supported. It’s like if you tried to explain time dilation to an ancient Greek, and they excitedly hopped on their fastest chariot thinking they could “fast forward” to the future, because time moves “more slowly” for you when you’re going faster, right?
I was thinking his wireless transmission, not harvesting… yeah, that is pretty out there.
No doubt there is plenty to discover, but there is a lot of B.S. that can be discarded, but people cling to it.
He also wanted to use the resonance for transmission AFAIK. He didn’t really buy into the radio waves from a scientific standpoint (which to be fair to him … everything was more theoretical back then; if he was in the modern era, he’d have better information to use).
This sort of thing is already being done with many commercial devices. See www.powercastco.com for one of the companies.
I think you might have meant powercastco.com
powercast.com just hangs for me and never completes the request.
Yes thank you! Edited my comment to correct it.
No radio expert here, but would’nt this at some point interfere with the transmissions if deployed at a large scale?
My guess is only in the sense that those radio waves, instead of reflected, they will be absorbed as energy. Partially.
Tale as old as time. And guess what will happen? Wifi signal strength will go down.
how exactly? What will physically happen?
Any receiving antenna is basically an energy harvesting device. Usually, it is specially designed to harvest just enough energy to actually receive the signal in order not to weaken the field. In the 2.4GHz spectrum, where WiFi and BT are at home, a sender is limited to 10mW of power. The more power energy harvesting devices draw from this field, the less will be available for other devices to actually receive the information.
Technically, an electromagnetic field of a frequency f will induce an alternating current in an antenna of length lambda/2 (or lambda/4 or even lambda/8, with less power received the smaller they get and lambda=wavelength=speed of light/frequency) that the receiver can “take out” at the antennas mid point and feed it into an amplification circuit.
Wouldnt the effect be very local? How far could the harvester affect the field? But i suppose it would be quite annoying if multiple people used something like that in densely populated area.
This ain’t free at all it’s more like stealing electricity with extra steps. Though if it does not degrade wifi or radio signal I’m up for it be used aside from just wasting away.
The dawn of the Matrix is almost here chunmers!
You mean… an antenna?
Wouldn’t this just decrease the reception for rf devices? Isn’t it just stealing power from the system to power other devices?
No more than any random objects.
Think of it like a solar panel. Yes, it blocks light from things behind it, but it doesn’t suck light from nearby.
That’s interesting! I thought that if you for example have a 50w RF transmitter, taking 40w from it would make it act as a 10w one for the other devices around it.
Thx for the explanation :3
It you could build a 40w antenna sure, but it’d basically have to be a dome surrounding the transmitting one at that point.
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I know of companies who have already tested and tried this our years ago, didn’t read the article but doesn’t seam very new to me
I would find this super cool if it wasnt for the fact that all of the radio frequencies are owned by the military and corporations. Outdoor IoT could be amazing, but it is kind of dead because you cant actually connect it to the internet without laying down cable or using 4G which is horrible for low power applications.
I don’t know what kind of idea you are getting. Radio and wi-ifi are waves. The wave is what can be used, you don’t care who generated it. To say it somehow the wave is in the air and you just take advantage of it being there to convert it to energy. Doesn’t matter what the wave could have been read as. In general a radio station is not going to stop working for a whole region just to stop you from using it.
Maybe i left out too much context.
Im not talking about the research itself, but about how it could be utilized.
Their idea (having small devices that can be powered by nothing but stray radiowaves) apparently works and is great by itself.
However its usefullness is limited if you cant somehow connect those devices with the rest of the world. Thats the issue im complaining about.
There are tons of small devices that don’t have to be connected to be useful. Lots of personal items or small sensors.
Anything that can be powered by this research, can also be powered by a button sized battery for weeks if not not longer. I thinks its more intended for very off grid stuff but maybe im just too uncreative.
Huh?
What are you asking for here? Some sort of worldwide free ISP?
There are already lots of concepts for low power wireless communication for example LoRaWAN The issue is not the ISP its the technology used to establish a connection between devices. We need hardware that can run with the low power requirements that come with this research.
That’s not any sort of legal issue stopping you, that’s physics. If you’re trying to create say, some sort of mesh network, and the device is using all of the signal’s power just to run itself, there’s no power left to retransmit. You don’t get something from nothing. We’re talking microamps and smaller with these devices.
If you’ve ever used a crystal radio, you can get an idea for how weakly powered stuff like this is.
Edit: look up the channel “EEVBlog” on YouTube, dude has a dozen videos on various such devices and goes into the actual math and viability of each.
This is the same take as people thinking wind energy steals wind, or solar energy reduces the sun’s efficacy.
Wind energy does.
It’s just that we can’t extract sufficient energy from it to have any meaningful impact.
Exactly my analogy.
Technically, a properly tuned receiver that’s using the signal for power can create radio “shadows” behind the device. People have also been caught with giant coils in their attic siphoning power from nearby radio stations and high voltage power lines, because they can detect the power draw.
They… have? Have a source? That sounds nuts!
You are confusing what i am talking about. See my other response.
Just use solar and batteries?🤷🏼♀️
