Scientists Create Super-Thin 'Sheet' That Could Charge Our Phones (theguardian.com) 116
An anonymous reader quotes a report from The Guardian: Scientists at Massachusetts Institute of Technology (MIT) have created super-thin, bendy materials that absorb wireless internet and other electromagnetic waves in the air and turn them into electricity. The lead researcher, Tomas Palacios, said the breakthrough paved the way for energy-harvesting covers ranging from tablecloths to giant wrappers for buildings that extract energy from the environment to power sensors and other electronics. Details have been published in the journal Nature. Palacios and his colleagues connected a bendy antenna to a flexible semiconductor layer only three atoms thick. The antenna picks up wifi and other radio-frequency signals and turns them into an alternating current. This flows into the molybdenum disulphide semiconductor, where it is converted into a direct electrical current. [M]olybdenum disulphide film can be produced in sheets on industrial roll-to-roll machines, meaning they can be made large enough to capture useful amounts of energy.
Ambient wifi signals can fill an office with more than 100 microwatts of power that is ripe to be scavenged by energy-harvesting devices. The MIT system has an efficiency of between 30% and 40%, producing about 40 microwatts when exposed to signals bearing 150 microwatts of power in laboratory tests. "It doesn't sound like much compared with the 60 watts that a computer needs, but you can still do a lot with it," Palacios said. "You can design a wide range of sensors, for environmental monitoring or chemical and biological sensing, which operate at the single microwatt level. Or you could store the electricity in a battery to use later."
Ambient wifi signals can fill an office with more than 100 microwatts of power that is ripe to be scavenged by energy-harvesting devices. The MIT system has an efficiency of between 30% and 40%, producing about 40 microwatts when exposed to signals bearing 150 microwatts of power in laboratory tests. "It doesn't sound like much compared with the 60 watts that a computer needs, but you can still do a lot with it," Palacios said. "You can design a wide range of sensors, for environmental monitoring or chemical and biological sensing, which operate at the single microwatt level. Or you could store the electricity in a battery to use later."
Is this new? (Score:1)
Hasn't this basically been a thing for a long time? Like those old spy microphones they'd power remotely
Re: Is this new? (Score:3, Informative)
Tesla did wireless power transmission at his Colorado Springs facility. It took a shyte ton of power to do it though. The distance between the transmission station an object being powered was less than a few city blocks.
The thing you are thinking about (and yes the scientist basically "discovered" a fancier version of tin foil) is the bug the Soviet Union put into a United States seal used in Russia at the end of WWII. It used no batteries nor external wired power source and could have ran forever had it no
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I love the "We are not advancing technically because this new technology is just a slight improvement over the older technology" trope.
We read the history books that list advancements often in decades blocks, we feel that we are just not advancing as much as we use to.
Because it seems like the Electric Light, the Telephone, the Radio came out in the same year and was used by all, people just rushed out to buy all this stuff. And a massive team of people just started putting up telephone and power poles to g
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AxeTheMax reminisced:
Way back when I was a boy and the fear was a new ice age and not hothouse earth, I used to make simple radios. I lived in north London about 5 miles from the BBC Brookmans Park transmitters. With a 25m long wire aerial, a simple tuner and no battery or other power, it was possible to get enough volume on a earphone for two or three people to gather round and listen to it to the main BBC channels, i.e. without putting it into your ear. Couldn't do the same with any of my small speakers though.
When my family moved to the Dayton, Ohio area in 1971, our first residence was a single-family rental the back yard of which ended at the fence around WHIO-FM's transmitter tower. My brother mounted bookshelf-style speakers (which I believe had 6-inch woofers) for his 8-track player (!) on the wall of his bedroom, at the back of the house. With his sound system powered down, you could clearly hear WHIO's broadcast over those speakers.
When I hear people (who inevitably also falsely claim
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There were already scientists warning about global warming in the 1800s.
You're not actually that old. You were merely surrounded by ignorance, the science hasn't changed.
Does this diminish useful signal power? (Score:5, Insightful)
Phone reception is already bad in a lot of buildings. Would not wrapping a giant layer of bar-feeding fabric around a building I am in make things even worse?
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Also, you'll deploy this and find that all of a sudden you have dark spots in your wifi coverage you didn't have before, because the radio waves are being absorbed by this material.
But hey, you can power up a phone or two at the cost of doubling or tripling your access point density!
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If they make giant umbrellas out of this stuff, I'd totally be willing to switch from a rain hat to umbrella.
In fact, I'd like to line the inside of my car with it, too, to top off the battery in case I don't drive for a long time.
And hey, if it is cheap enough to line the walls, I could reduce interference and reduce my access point density!
I can't really see why you'd install it in between your access points, instead of at the perimeter.
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It had me smiling for the same reason you're complaining; expect this technology to be popular!
Phone addiction in title. (Score:4, Insightful)
Diode (Score:5, Interesting)
...bendy antenna to a flexible semiconductor layer only three atoms thick...
I believe this is called a diode and we've been converting signals to electricity with them for a very long time (rectifiers). Seems like what they've done is come up with a way to incorporate them into an antenna that could be manufactured in large flexible sheets suitable for deployment on available flat surfaces. Interesting.
Diode [wikipedia.org]
Re:Diode (Score:5, Interesting)
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Old ideas.
Sure, but the real innovation here is not that they built an ambient energy harvester, but that it is "bendy".
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You can harvest small amounts of energy with a basic FM/TV antenna, rectifier diode and a few voltage doubler stages (simple diode and capacitor).
The issue is that you need a fairly large antenna that is pointed in the right direction. Any improvement, such as a smaller, less directional antenna and lower power electronics to power gets us closer to devices that can run from ambient RF power for extremely long periods of time.
For example you could have a smoke/carbon monoxide alarm that could last for decad
Re: Diode (Score:2)
Photons? Radio waves are electromagnetic energy, a diode will crudely convert it into DC power, thats essently what a crystal radio does to produce electrical currents to drive a headset. So yes a big coil and a diode will convert radio into electrical power all beit small. The Rugby MSF long wave radio beacon,and several tv transmitter towers in the vhf days often had to deal with enterprising growers using an old bed frame and a big ass diode, to create astonishing amounts of free power to heat thier gre
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This. The design is that these frequencies penetrate walls so cell phones are actually useful. While sucking up such for energy is clever, if they have to coat walls and floors with it, so much so it interferes, that would be an issue. And, as regulator of use of fequencies...
Radio makers have to build little rf-opaque rooms to test micro broadcasts, but to prevent the escape of the signal more than block incoming.
can't charge a phone (Score:1)
Not with microwatts...
Re: can't charge a phone (Score:2)
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Hospitals and long-term care centers usually have telephone service, though.
fake news again . (Score:4, Funny)
Reading about this elsewhere, I believe that the scientists specifically said that this is far from enough power to operate a cell phone. But without the mention of a cell phone, who would waste time on this 'news'?
Furthermore- if you did wrap one of these around your phone, how would it get the radio signals it needs to function?
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Re:fake news again . (Score:5, Informative)
No, you wrap it around your head, and run a wire to your phone. It blocks mind control rays and powers your phone at the same time
Re:fake news again . (Score:4, Interesting)
I think the idea is that you would put this on surfaces inside a home or office. The problem is that these radio waves are not "free energy" - there are potentially devices that want to receive those radio waves that will no longer be able to if this is deployed between them and the transmitter.
So now you are buying more access points and transmitters (and plugging them in, and powering them up) to cover the dead spots you just created in order to recharge your phone with "free" energy.
Or you could just plug in your $10 phone charger like all of us have been doing for 20 years and skip overhauling your (and other people's) wireless infrastructure.
TANSTAAFL (Score:1)
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this is not 'free energy', it gets popular enough and some broadcasters would start demanding some sort of payment
For 100 microwatts? I pay 10 cents per kwhr. So that comes out to 1 cent for every 100,000 hours = 11 years.
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You pay for the convenience of not being tethered to a power socket.
Unfortunately 100uW is too small to actually make any appreciable difference to your phone's battery life. I did some experiments years ago and if you have a decent set-top antenna pointed at the transmitter you can run a small LCD clock.
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100uW is more than enough to run a microcontroller. For example, the popular ATTINY85 uses 4uA in power-down mode with the watchdog timer active which can give you a periodic interrupt.
It uses 1mA when active. So at 2.8V that would be 280uW while active. You only need to keep the duty cycle below 20% or so.
You could even power a short wireless transmission every 10 minutes or something.
So for a use case, maybe an RFID with built-in temperature sensor for use in refrigerated supply chain applications. The fl
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Sorry for my mistake, I said "280uW" instead of 280mW" so the duty cycle would be much lower. But you could still power a short wireless transmission every 10 minutes.
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You are a factor of 10 out, 1mA at 2.8V is 2800 microwatts. 1% duty cycle might be possible, but 100uW is optimistic and also doesn't account for losses after harvesting because the harvesting circuit won't give you a regulated 2.8V.
It's still possible to use for some applications, but if you have the option then solar is likely to be a better bet.
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For 100 microwatts?
You're overlooking the terrible conversion between power sent into the transmitting antenna and the power that's actually coming into the room where you're sitting.
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In other words: what are the effects when you scale this up massively?
When you scale 100 microwatts up a million-fold you get ... 100 watts. Enough to power a lightbulb.
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Scientists say one thing (Score:5, Insightful)
Journalists say another.
They said it can power tiny sensors that use microwatts of power.
The headline literally claims a million times that, says it could charge a phone.
congrats, you invented the antenna (Score:4, Insightful)
yes, conductors turn radio waves into electricity, that's what happens in antenna. very bad to be absorbing large amounts, that means you're blocking them and attenuating them.... bad for everyone's wifi, bluetooth, broadcast radio reception, etc.
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yes, conductors turn radio waves into electricity, that's what happens in antenna. very bad to be absorbing large amounts, that means you're blocking them and attenuating them.... bad for everyone's wifi, bluetooth, broadcast radio reception, etc.
Yeah, that was my thought; if you're extracting power, you're killing the signal. However, it might be a great idea to incorporate something like this into the walls in apartment complexes. A little "free" power and it will also reduce Wifi bandwidth contention by damping signals. But putting lots of it inside your house seems like it will just create a lot of Wifi dead zones.
Maybe you could make clothing from it (Score:2)
very bad to be absorbing large amounts, that means you're blocking them and attenuating them
It seems like WiFi absorbing clothing would be really popular with people that claimed they could feel WiFi or cell signals passing through their body...
Yes and no (Score:2)
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Maths? (Score:2)
What don't I understand here? How is 40uW out of 150uW 30 to 40% efficiency?
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What don't I understand here? How is 40uW out of 150uW 30 to 40% efficiency?
If you rounded it to the nearest 10%, 26.666%.
But 30-40 already suggests an error range.
"Wireless Internet" (Score:1)
How do they know it's wireless internet as opposed to any other traffic running over IP?
People at MIT are really smart so they should know.
this will be illegal (Score:2)
because harvesting EM radiation for free to power your sensors removes that power from the transmission. This means that the general distance to which the signal usually travels is shortened. The emitter will not be happy to need to increase power output to get his signal along only because there are power harvesters along the line.
These authors are engineers, not scientists (rant) (Score:3)
These aren't scientists. There are 18 authors and 15 are affiliated with electrical engineering departments, one with chemical engineering, one with chemistry, and one with physics. 16 out of 18 are engineers and the author of the article classifies them all as "scientists. God I get fucking tired of this.
Nice (Score:2)
" giant wrappers for buildings that extract energy "
The cellphone and wireless-free building where the 'radiation-sensitive' people can live.
Seems interesting (Score:4, Informative)
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Hey, I already invented this!!! (Score:1)
Brilliant in its uselessness (Score:2)
The average smartphone uses 268 milliwatts at idle, screen off. 40 microwatts is hardly worth it.
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If it continuously charges you will be running topped off most of the time.
But these amounts aren't enough to keep up with ambient battery loss while the phone is off.
It is not for phones (Score:2)
But for small/embeddable sensors, smart dust, or things like that, for smart homes, cities and clothing, and/or for pervasive surveillance, they might fit.
MIT funding drives. Nothing to see here. (Score:2)
MIT is notorious for these miracle breakthrough news releases about the same time every year. And the miracles, even many years later, never see the light of day. I should start a website detailing them.
They're Right! (Score:2)
40 microwatts doesn't sound like a lot of power. That's barely even enough to be called power imo. Lol!
Faraday Cage the Cellphone so it dies faster (Score:2)
Umm maybe this didn't occur to the designers but sure you might be able to sap a little more power to charge the cellphone but I'll bet you'll be losing a lot more from the cellphone desperately trying to find a cell tower to connect to because you've killed it's signal reception.