4 ms·

Charging capacitors from thermal fluctuations using diodes

39 points by toss1 3y ago

berbec 3y ago
Could someone with knowledge of this ELI5 for me? It seems that this is the way Douglas Adams' Finite Improbability Generator functions. [1] 1: "The principle of generating small amounts of finite improbability by simply hooking the logic circuits of a Bambleweeny 57 Sub-Meson Brain to an atomic vector plotter suspended in a strong Brownian Motion producer (say a nice hot cup of tea) were of course well understood"
srean 3y ago
Isnt this Maxwell's demon ? The paper is pay-walled so could not read the mandatory discussion on 2nd law of thermodynamics. The underlying idea is not new. Brillouin published Can the Rectifier Become a Thermodynamical Demon? in 1950 [0] [1]. I hope these are cited in the paper. [0] https://journals.aps.org/pr/abstract/10.1103/PhysRev.78.627.2 https://journals.aps.org/pr/abstract/10.1103/PhysRev.78.627.... [1] https://pubs.aip.org/aip/apl/article-abstract/14/2/54/41611/SPONTANEOUS-REVERSE-CURRENT-DUE-TO-THE-BRILLOUIN https://pubs.aip.org/aip/apl/article-abstract/14/2/54/41611/... https://en.wikipedia.org/wiki/Maxwell%27s_demon https://en.wikipedia.org/wiki/Maxwell%27s_demon https://en.wikipedia.org/wiki/Brownian_ratchet https://en.wikipedia.org/wiki/Brownian_ratchet
- loa_in_ 3y ago
  Reminds me more of the self winding watch mechanism [1] but using the ever vibrating world we also need to live instead of the locomotion of the wearer. [1] https://en.wikipedia.org/wiki/Automatic_watch https://en.wikipedia.org/wiki/Automatic_watch
- Extigy 3y ago
  There’s a non-paywall version on arXiv: https://arxiv.org/abs/2308.09083 https://arxiv.org/abs/2308.09083 The paper you mention is indeed cited.
  - Animats 3y ago
    "A series of these units may be built on an integrated circuit with each using a space of less than 0.1 square microns, with the potential to produce a significant power density." Huh. Is this for real? Most of the discussion assumes an ideal diode. Real diodes have diode drop. All this is powered by very small fluctuations, right. They'd have to overcome the diode drop. (There is a real component called an "ideal diode", which is a power MOSFET with control circuitry to turn it on when the voltage is higher in the forward direction. MOSFETs have ON resistances in millohms, which is better than diodes can do. Often used with solar powered battery chargers, large DC-DC converters, etc. Not sure that applies here.)
isoprophlex 3y ago
What is this?! Maxwells Demon, battery edition?!
- pro-kythera 3y ago
  Maxwell's Diode.
outsomnia 3y ago
... I was going to write it off as someone just diddling themselves with simulating ideal components > Of course, real diodes leak in the low conducting region, and the system will eventually relax to thermal equilibrium. ... but at the end they have Appendix F with an "experiment" on a "TSMC chip" showing an impulse to 300mV.
- outsomnia 3y ago
  There's an article with much better background on the whole thing and how they're trying to commercialize it https://scitechdaily.com/long-considered-impossible-in-physics-nonlinear-circuit-harvests-clean-power-using-graphene/ https://scitechdaily.com/long-considered-impossible-in-physi...
  - qa_acc 3y ago
    I just finished to read the article and I find it hilarious: - Author: "They can also operate in many environments, making them particularly attractive for wireless sensors in locations where changing BATTERIES is inconvenient or expensive, such as an underground pipe system or interior aircraft cable ducts"; - CEO: "There is broad demand across the electronics industry to shrink form factors and decrease dependency on BATTERIES and wired power. We believe Graphene Energy Harvesting will have a profound impact on both.” We really live in a "bullshit amplified by social" society, they took a scientific publication about a phenomenon that needs peer reviews , verifications, etc and transform it in "We have the technology to recharge your phone WITH THE HEAT of YOUR HAND, licenses available !"
  - ars 3y ago
    Thanks for finding that, but that explained exactly nothing about how they are overcoming the 2nd law.

39 points by toss1 3y ago

Could someone with knowledge of this ELI5 for me? It seems that this is the way Douglas Adams' Finite Improbability Generator functions. [1] 1: "The principle of generating small amounts of finite improbability by simply hooking the logic circuits of a Bambleweeny 57 Sub-Meson Brain to an atomic vector plotter suspended in a strong Brownian Motion producer (say a nice hot cup of tea) were of course well understood"

srean 3y ago

Isnt this Maxwell's demon ? The paper is pay-walled so could not read the mandatory discussion on 2nd law of thermodynamics. The underlying idea is not new. Brillouin published Can the Rectifier Become a Thermodynamical Demon? in 1950 [0] [1]. I hope these are cited in the paper. [0] https://journals.aps.org/pr/abstract/10.1103/PhysRev.78.627.2 https://journals.aps.org/pr/abstract/10.1103/PhysRev.78.627.... [1] https://pubs.aip.org/aip/apl/article-abstract/14/2/54/41611/SPONTANEOUS-REVERSE-CURRENT-DUE-TO-THE-BRILLOUIN https://pubs.aip.org/aip/apl/article-abstract/14/2/54/41611/... https://en.wikipedia.org/wiki/Maxwell%27s_demon https://en.wikipedia.org/wiki/Maxwell%27s_demon https://en.wikipedia.org/wiki/Brownian_ratchet https://en.wikipedia.org/wiki/Brownian_ratchet

loa_in_ 3y ago
Reminds me more of the self winding watch mechanism [1] but using the ever vibrating world we also need to live instead of the locomotion of the wearer. [1] https://en.wikipedia.org/wiki/Automatic_watch https://en.wikipedia.org/wiki/Automatic_watch
Extigy 3y ago
There’s a non-paywall version on arXiv: https://arxiv.org/abs/2308.09083 https://arxiv.org/abs/2308.09083 The paper you mention is indeed cited.
- Animats 3y ago
  "A series of these units may be built on an integrated circuit with each using a space of less than 0.1 square microns, with the potential to produce a significant power density." Huh. Is this for real? Most of the discussion assumes an ideal diode. Real diodes have diode drop. All this is powered by very small fluctuations, right. They'd have to overcome the diode drop. (There is a real component called an "ideal diode", which is a power MOSFET with control circuitry to turn it on when the voltage is higher in the forward direction. MOSFETs have ON resistances in millohms, which is better than diodes can do. Often used with solar powered battery chargers, large DC-DC converters, etc. Not sure that applies here.)

isoprophlex 3y ago

What is this?! Maxwells Demon, battery edition?!

pro-kythera 3y ago
Maxwell's Diode.

outsomnia 3y ago

... I was going to write it off as someone just diddling themselves with simulating ideal components > Of course, real diodes leak in the low conducting region, and the system will eventually relax to thermal equilibrium. ... but at the end they have Appendix F with an "experiment" on a "TSMC chip" showing an impulse to 300mV.

outsomnia 3y ago
There's an article with much better background on the whole thing and how they're trying to commercialize it https://scitechdaily.com/long-considered-impossible-in-physics-nonlinear-circuit-harvests-clean-power-using-graphene/ https://scitechdaily.com/long-considered-impossible-in-physi...
- qa_acc 3y ago
  I just finished to read the article and I find it hilarious: - Author: "They can also operate in many environments, making them particularly attractive for wireless sensors in locations where changing BATTERIES is inconvenient or expensive, such as an underground pipe system or interior aircraft cable ducts"; - CEO: "There is broad demand across the electronics industry to shrink form factors and decrease dependency on BATTERIES and wired power. We believe Graphene Energy Harvesting will have a profound impact on both.” We really live in a "bullshit amplified by social" society, they took a scientific publication about a phenomenon that needs peer reviews , verifications, etc and transform it in "We have the technology to recharge your phone WITH THE HEAT of YOUR HAND, licenses available !"
- ars 3y ago
  Thanks for finding that, but that explained exactly nothing about how they are overcoming the 2nd law.