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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
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.