Scientists find that ice generates electricity when bent | Hacker News Reader

Scientists find that ice generates electricity when bent

phys.org

86 pointsisaacfrond25 comments

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Reminds me of x-ray getting generated when you peel off a duct tape or something.

Scotch tape in a vacuum: https://www.technologyreview.com/2008/10/23/217918/x-rays-ma...

I think wintergreen lifesavers emit light when you crunch them.

Triboluminescence in wintergreen mints: https://www.youtube.com/watch?v=BckJfovkxOc

Quartz: https://en.wikipedia.org/wiki/File:Tribo.ogv

I've been able to see this by going into my driveway at night, by picking up some quartz gravel, jumping up and throwing the gravel down as hard as I can directly towards the ground (where it impacts other gravel).

I think wintergreen lifesavers emit light when you crunch them.

That's how you get girls to agree to turn off the lights when playing post office.

https://en.wikipedia.org/wiki/Post_office_(game)

Once upon a time, I was peeling a banana in a dim and very dry room, and I'm pretty sure I saw a spark, perhaps caused by the same phenomenon.

Very cool! From cursory research it seems like many salicylates produce triboluminescence (I don't know why), and some people online with special dietary needs say that bananas are high in salicylates (though it seems controversial). So that would be my hypothesis.

I'm gunnuh try crushing an aspirin (acetylsalicylic acid) and see what happens. (ETA: My headache pills that have aspirin, acetaminophen, and caffeine, along with whatever binders, did not produce any light that my camera detected. That's the only aspirin I have and I'm only willing to sacrifice one of them. Oh well!)

ETA2: Wasn't able to get it to work by peeling a banana, crushing the inside, or crushing the peel, but I don't doubt it happened. Bananas probably vary a great deal. Thanks for the fun diversion, I haven't done an experiment like this in years.

> Bananas probably vary a great deal.

Yep, and I probably should have mentioned, this was one of those giant, GMO-esque bananas, and it had a very thick, perhaps 1 cm skin, the interior of which was kinda fuzzy, such that peeling it was reminiscent of pulling apart velcro.

triboluminescence https://www.nytimes.com/2007/06/19/science/19winto.html

Geologic electrochemistry?

Dupes:

https://news.ycombinator.com/item?id=45092444

https://news.ycombinator.com/item?id=45273032

I swear this news popped up a few months ago as well.

I feel like the “bending ice makes electricity” bit is years, if not decades, old. Now I’m off to explore the rabbit holes and understand my own memory.

I searched as much as I could but couldn't find anything. Please let me know, I feel like my memory is faulty.

Poking at this dissertation (Continuum and Computational Modeling of Flexoelectricity by Sheng Mao):

https://repository.upenn.edu/server/api/core/bitstreams/3bc2...

> Flexoelectricity, ever since its discovery, has been regarded as an alternative of piezoelectricity at small scales. In fact, as early as the 1960s, Koehler et al. (1962), Turch´anyi, G. et al. (1973), Whitworth (1975) found that edge dislocations in centrosymmetric materials, such as sodium chloride, carry charge. Later, Perenko & Whitworth (1983) extended the observation to another kind of centrosymmetric material, ice. Piezoelectricity vanishes in these materials, therefore cannot be the source. Instead, a “pseudo-piezoelectric” effect was postulated by Evtushenko et al. (1987) for an explanation, which was later shown to be a result of flexoelectricity Mao & Purohit (2015).

Emphasis added.

So I think this was known but not fully understood by the time Perenko & Whitworth published Electric currents associated with dislocation motion in ice in 1983?

https://scholar.google.com/scholar?cluster=69134483967663101...

> In this paper we describe [an] experiment in which a small current is observed due to the movement of dislocations during plastic deformation [of ice].

The same authors of the paper TFA discusses published a preprint in 2022, which could also be what you're thinking of: https://arxiv.org/abs/2212.00323

Sit downhill of a glacier. Collect power as it slowly crumbles.

Use the pyramids' angles to do the same...

> This discovery could have significant implications for the development of future technological devices

I whish science could stop having to make bullshit claims to get funding. This kind of research is cool because it explain the world we live in, it's doesn't have to be a pathway to technological devices to be legitimate.

It's cool also because ice.

I could envision significant energy production for this technology near glaciers or ice sheets with lots of melt activity. Admittedly not really a market, but worth exploring for future applications (eg on icy moons)

The amount of electricity is tiny, probably less than https://en.wikipedia.org/wiki/Piezo_ignition and difficult to isolate because it will like to partially melt and the electricity will go in unexpected direction.

The idea to use this to explain some of the electricity generated in thunderstorms looks less impossible, but the new discovery is for temperatures below -113ºC (160K) (-171ºF), so probably too cold for Earth but may be there are some weird thunderstorms in Pluto.

I would think there's some amount you could capture inductively or magnetically, but perhaps it's too small to be useful. Still, feels like fundamental enough science to look into.

I agree that it's interesting. I used to tell people about giant magnetoresistence https://news.ycombinator.com/item?id=9908855 until the SSD people ruined the punch line.

I'm not sure if the IceCube team https://en.wikipedia.org/wiki/IceCube_Neutrino_Observatory may find it interesting.

Anyway, I don't expect it to be a useful method to harvest energy.

> Still, feels like fundamental enough science to look into.

That's exactly my point.

Science doesn't need to be applicable to be worth doing.

If it has applications I would guess they would be some form of geotechnical data, like measuring the stress within a glacier (if that's interesting for some reason).

Draft grant proposal - power a giant van de graaf generator by dropping asteroids onto the artic ice cap.

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