In no way is this a discovery.
This is what crystal diode radios are from the '40s.
Some guy built one in Japan, it’s basically just a thousand transceivers in a box hooked up to a USB port harvesting radio/wifi signals.
Here’s a guy using them to make light:
It’s super cool, but not a discovery.
This would be neat for a bunch of passive IoT buttons. No need for a piezo to generate power, good for a couple presses at a time, just simple stuff like that.
Charge up a capacitor and allow a single button press to send a radio signal. Or maybe have enough power to send a WiFi signal.
You’re right, that would be the preferred application atm.
I wonder if it could power a sensor. Something like a soil dampness or thermometer, where you only need a few updates per day. Could be pretty cool for passive monitoring applications.
I remember making a crystal diode radio with my dad as a kid. You can still buy kits for those.
From Radio Shack?!
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.
It’s realized, just not scaled.
I was a little careless with how I phrased that. They said in the article they’ve done it, but it’s not “realized” in the sense that it’s not to a level of practicality that they’d want it to be. It can currently harvest signals to -20dBm, but they think they can get that to -62dBm for greater efficiency.
The main hurdle, according to them, is there’s no schottky diode that fits their needs, and they’ll have to engineer a new variant (at the nano scale…?). So, still a theoretical possibility on a more practical level, but this is hopeful news nonetheless.
I agree, it’s still very hopeful news that this type of research is being conducted at all, I’m still looking forward to transceivers being built into cell phone batteries and slowly trickle charging constantly.
Without tracking: https://youtu.be/_pm2tLN6KOQ
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.
No, this is transforming focused radio waves into DC voltage using a transceiver, Rather than Tesla’s ambient electricity harvested from the atmosphere.
This sort of thing is already being done with many commercial devices. See www.powercastco.com for one of the companies.
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.
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
The dawn of the Matrix is almost here chunmers!
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?
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.
You are confusing what i am talking about. See my other response.
Just use solar and batteries?🤷🏼♀️
