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Physicists Build Circuit That Generates Clean, Limitless Power from Graphene (2020)
- charles_f 5y agoNope. Not reproduced since then. One of these classic "hey I've discovered an effect that is not properly isolated and contradicts brownian motion. Everything we know is probably wrong, let's publish about it rather than try to understand what we screwed up" moments.
- joak 5y agoExcerpts： "A team of University of Arkansas physicists has successfully developed a circuit capable of capturing graphene's thermal motion and converting it into an electrical current." "The idea of harvesting energy from graphene is controversial because it refutes physicist Richard Feynman’s well-known assertion that the thermal motion of atoms, known as Brownian motion, cannot do work."
- hanniabu 5y agoSounds like a piezo sensor
- willis936 5y agoAs a freshman EE I suggested this as a potential source of power. Got bad marks on the assignment. There's nobody to give this research group bad marks.
- hahaimdumb 5y ago
- willis936 5y agoExtracting power from no gradient is definitively a perpetual motion machine. This concept fails at a high level even before diving into the weeds. No authority is needed. Closing the feedback loop would help separate the wheat (science) from the chuff (pseudoscience). https://youtu.be/rckrnYw5sOA https://youtu.be/rckrnYw5sOA
- hahaimdumb 5y ago
- willis936 5y agoThere is an awful lot of projection going on here. I'd focus on the content. Prove that extracting power from no gradient of any kind is possible. If this request doesn't set off alarm bells in your head: I think the audience knows who is out the their depth.
- wrycoder 5y agoThe thermal motion of atoms in a coal fire can do work just fine. All you need is a steam engine and a cold reservoir.
- vba616 5y agoIt seems odd to mention Feynman here even if he did say it. Surely he wasn't the only or first person?
- sedatk 5y agoSurely he was joking.
- mwt 5y agoMaybe this is it? > first analysed in 1912 ... by Polish physicist Marian Smoluchowski. ... popularised by [Feynman] in a physics lecture at the California Institute of Technology on May 11, 1962, https://en.wikipedia.org/wiki/Brownian_ratchet https://en.wikipedia.org/wiki/Brownian_ratchet
- kergonath 5y agoIt’s an allusion to the Brownian ratchet thought experiment. AFAIK he demonstrated why it does not work.
- bongoman37 5y ago
- joak 5y agoProducing electricity from Brownian motion ?!
- The_rationalist 5y agoIt's been two years, what is their progress? It has probably failed to be exploitable then ?
- westurner 5y agoScholarlyArticles that cite "Fluctuation-induced current from freestanding graphene" (2020) https://scholar.google.com/scholar?cites=3748350803951231734&as_sdt=5,43&sciodt=0,43&hl=en https://scholar.google.com/scholar?cites=3748350803951231734...
- polemic 5y agoQuick Google search finds the concept being used in medical sensors. https://www.sciencedaily.com/releases/2022/03/220301205420.htm https://www.sciencedaily.com/releases/2022/03/220301205420.h... When correctly shaped, graphene can harvest energy from motion, such as human body movements, and store it as electrical energy in micro-supercapacitors.
- civilized 5y agoMotion is one thing, thermal motion is another. Clocks that wind themselves up from being jostled around are centuries old. But thermal energy is supposed to be maximally disordered and thus unable to be converted to a more ordered form like electricity.
- pmoleri 5y agoPrevious discussion 2020-10: https://news.ycombinator.com/item?id=24671279 https://news.ycombinator.com/item?id=24671279
- BlueMatter5 5y agoOr less than 24h ago: https://news.ycombinator.com/item?id=30817793 https://news.ycombinator.com/item?id=30817793 (same article, different domain) With a link therein to another post less than a month ago.
- deleted 5y ago[deleted]
- curious_cat_163 5y agoLimitless energy? Doesn’t that violate the first law? Is this clickbait? Or, is there actual basis to the claim? Kindly, someone who knows about this space elaborate?
- plebianRube 5y agoI would read the article, it is easy to read and accessible. Here's the meat though. "Thibado’s team found that at room temperature the thermal motion of graphene does in fact induce an alternating current (AC) in a circuit, an achievement thought to be impossible. According to Kumar, the graphene and circuit share a symbiotic relationship. Though the thermal environment is performing work on the load resistor, the graphene and circuit are at the same temperature and heat does not flow between the two. That’s an important distinction, said Thibado, because a temperature difference between the graphene and circuit, in a circuit producing power, would contradict the second law of thermodynamics."
- curious_cat_163 5y agoThanks
- willis936 5y agoA circuit producing power without a temperature difference contradicts the second law of thermodynamics, which is what Thibado is claiming to have done.
- roywiggins 5y agoHard to see how this works when Brownian ratchets don't. Also: "Léon Brillouin in 1950 discussed an electrical circuit analogue that uses a rectifier (such as a diode) instead of a ratchet. The idea was the diode would rectify the Johnson noise thermal current fluctuations produced by the resistor, generating a direct current which could be used to perform work. In the detailed analysis it was shown that the thermal fluctuations within the diode generate an electromotive force that cancels the voltage from rectified current fluctuations. Therefore, just as with the ratchet, the circuit will produce no useful energy if all the components are at thermal equilibrium (at the same temperature); a DC current will be produced only when the diode is at a lower temperature than the resistor." https://en.wikipedia.org/wiki/Brownian_ratchet https://en.wikipedia.org/wiki/Brownian_ratchet
- analog31 5y agoDid this team discover Johnson noise?
- catlifeonmars 5y agoTFW you see “Limitless” and “Power” in the same sentence.
- TeeMassive 5y agoI didn't read the whole article, but from the schematics it looks like they are exploiting thermal electronic noise and applying a half-bridge rectifier to it so it produces very low voltage power. On one hand, it's clearly bullshit due to the extravagant title claiming to violate the 2nd law of thermodynamics. On the other hand, if a system is sufficiently small than it can violate the 2nd law, locally. It seems the tour de force in this case is that the scale can be somewhat enlarged by the very low power of thermal electronic noise.
- n8ta 5y ago“This means that the second law of thermodynamics is not violated, " -Paul Thibado, professor, physics. Title is awful ofc but the actual scientist of course never claimed this.
- nborwankar 5y agoIs this meant to be an early April Fools joke?
- deleted 5y ago[deleted]
- dboreham 5y agoThat was easy.
- Animats 5y agoThis is from 2020. Since the followup isn't "Arkansas Graphene Power 10GW plant comes online", it probably doesn't generate "clean, limitless power".
- godelski 5y agoAt least not cheaply. As far as I'm aware (may be wrong) we still are unable to build graphene at scale, let alone graphene circuits.
- tbrownaw 5y agoA previous time this came up, I had the impression that what it really does is extract energy from a temperature difference between the graphene and the load, which is in principle perfectly normal even is it's a new way to arrange the details. Edit: missed the link to the abstract. > However, there is power dissipated by the load resistor, and its time average is exactly equal to the power supplied by the thermal bath. So yeah, extracting power from a thermal bath sounds exactly like capturing energy as it flows down a temperature gradient.
- mlindner 5y agoHeadline like these are automatically ignorable. Why is this even upvoted. "Limitless" power is just always false.
- steve_adams_86 5y agoEven in utopian depictions of the future energy tends not to be limitless. Extremely abundant maybe, but never limitless. It seems strange to even pursue it.
- mlindner 5y agoIn any possible Utopian future, our energy usage will expand to match our energy production. As more energy is produced, more uses is found to use it.