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Scientists Create Super-Thin 'Sheet' That Could Charge Our Phones (theguardian.com)
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."
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?
"There is more worth loving than we have strength to love." - Brian Jay Stanley
We need a cure before it gets out of hand. How much energy does it take to make something practical out of this vs how much you might get over it's lifespan? I wonder if a paper-sized sheet could power a mechanical clock. Hey the clocked stopped, the wifi must be down :D
...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
I am not interested in articles about life extension advancements.
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?
...omphaloskepsis often...
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.
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.
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.
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 not been discovered.
https://en.wikipedia.org/wiki/The_Thing_(listening_device)
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.
const int one = 65536; (Silvermoon, Texture.cs)
SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
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.
But if they wrap buildings in this stuff they will be effectively creating Faraday Shields that interfere with rf propagation. And they will also be creating massive capacitors if wrapped buildings are across from each other.
E Proelio Veritas.