[HN Gopher] New material that can absorb and release enormous am...
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New material that can absorb and release enormous amounts of energy
Author : prostoalex
Score : 83 points
Date : 2022-02-02 18:53 UTC (4 hours ago)
(HTM) web link (phys.org)
(TXT) w3m dump (phys.org)
| marto1 wrote:
| Can it be used for batteries ? I know large scale mechanical
| batteries are a very efficient way of storing energy, but no idea
| about the state of small scale ones.
| fghorow wrote:
| Personally, I want a wind-up EV! ;-)
| capableweb wrote:
| Without reference, it's hard to know exactly what you mean with
| large scale vs small scale, but I do know a person who has a
| pool of water high up on their property, which they let run to
| the bottom pool when they want cheap energy when prices are
| high and pump it up again when prices are cheap but they have
| no need for it currently. I'd say that's relatively small
| scale.
| stavros wrote:
| That's a good energy storage mechanism, but do you know what
| the efficiency is? Also, how much energy could you
| practically store there?
| mwcremer wrote:
| Bigger scale:
| https://en.m.wikipedia.org/wiki/Helms_Pumped_Storage_Plant
| davedx wrote:
| No numbers whatsoever. Kind of a useless article
| pmayrgundter wrote:
| Source pub, with some videos of the loading response:
|
| https://www.pnas.org/content/119/1/e2118161119
| [deleted]
| mrfusion wrote:
| Can it be used for shock absorbers or seat belts?
| vimax wrote:
| Reading the paper my first thought was, could this be scaled up
| for a a tactile touch screen display?
| beambot wrote:
| Just to be clear: This appears to be mechanical storage (i.e.
| Hooke's Law) rather than _electrical_ storage. They 're embedding
| magnets into elastomers to create a programable "metamaterial"
| that has controlled non-linearities in elastic response.
| mrkstu wrote:
| Intersting material.
|
| More interesting to me is the Army being willing to sponsor
| research simultaneously with a Chinese institution...
| sybercecurity wrote:
| Often it is done simply to get reports. The research is likely
| going to happen anyway in a lot of these areas. Signing a deal
| to give some money commits the researchers to give reports used
| to monitor the program.
| ISL wrote:
| I was surprised to see that, too. It is a rare combination,
| perhaps a hopeful one if there are problems that funding
| agencies in both countries see as important-enough to fund
| alongside their frequently-presumed competitor.
|
| However, a closer read suggests that the author did the work at
| UMass Amherst, then took a professorship in Shenzhen.
| henryw wrote:
| Can this be made into bulletproof clothing that looks like normal
| clothes? That would be cool
| petermcneeley wrote:
| Joules per Kg or gtfo.
| stevespang wrote:
| natnatenathan wrote:
| I was hoping it would be called Astrophage...
|
| ref: https://en.wikipedia.org/wiki/Project_Hail_Mary
| Nition wrote:
| Not quite the same, but got me thinking: Could we theoretically
| power and refuel car in the following way:
|
| - Take a cube of X elastic material and squish it really dense
| with a big machine.
|
| - Power the car via the pressure of the material trying to
| expand.
|
| - Once it's nearly depleted (fully expanded), take it to another
| squishing station.
|
| I imagine you couldn't store anywhere _near_ enough power that
| way today, but then that 's also the kind of problem the linked
| material is trying to solve, right?
| hrez wrote:
| https://en.wikipedia.org/wiki/Compressed_air_car
| jiggawatts wrote:
| Compressed air energy storage is already a thing!
|
| The energy stored is limited by the tensile strength of the
| container. The best capacity for a unit weight is from
| laminated carbon fibre tanks, but this still doesn't even
| approach the energy density of ordinary hydrocarbon fuels.
|
| You'll find that there's lots of interesting ways to store
| energy -- like flywheels or chemical cells -- but one way or
| another they're all inherently limited by _chemical bond
| strengths_.
|
| Fundamentally all energy storage is some sort of stored
| "tension" in chemical bonds that can be released to do useful
| work.
|
| The reason fuels are so good is that this release needs a
| second component (oxygen) that is kept separated. This makes
| high energy densities safe.
|
| No separation -- like with compressed gas -- means that the
| energy storage is a bomb waiting to go off. It would be too
| dangerous to use.
| Nition wrote:
| Thanks, yeah that makes complete sense. Plus I would imagine
| the more energy density you need, the heavier your enclosure
| has to be, always partially negating the benefit!
| sidpatil wrote:
| The actual paper: https://www.pnas.org/content/119/1/e2118161119
| halpert wrote:
| It would be great if this material could help with brain damage
| in contact sports by making helmets better.
| abeppu wrote:
| That's a very specific application.
|
| Isn't there a bound on the efficacy of a helmet based on its
| size / thickness? I.e. your head's initial velocity and the
| thickness of the helmet constrain the distance over which your
| head's velocity must drop to zero, so there's some minimum
| force that must be applied to your head no matter what the
| helmet's material is?
| kbelder wrote:
| Conclusion: The helmets must be bigger, much bigger.
|
| I don't know their current thickness; maybe 2 cm? If we
| expand that to a cushioned 10-20cm all the way around their
| head, the force would be reduced by a factor of five to ten.
| I'd imagine they could head-butt all day long without damage,
| and football games would be much more entertaining.
| MarcoZavala wrote:
| [deleted]
| eointierney wrote:
| Helmets have an interesting correlation with concussion. They
| can help a lot in cycling, hurling, and f1, but can encourage
| reckless collision seeking in american football for example.
| Contact sports are intrinsically dangerous and introducing
| protection from one type of damage can allow increase in other
| damage forms.
|
| Avoid collisions
|
| I reckon rugby must change the most, which is a real shame
| because rugby at the highest level is amazing
|
| Though ice hockey is pretty daft
| politician wrote:
| I'm surprised they call it a metamaterial when the features are
| on the order of millimeters.
| MengerSponge wrote:
| The length scale of a metamaterials' features should be
| complementary to the length scale the metamaterial is acting
| on.
|
| Kind of squirrely, and I tried really hard to phrase that so it
| isn't a tautology. But if you're dealing with radio waves, your
| metamaterial can have _huge_ (meter-scale) features. If you 're
| dealing with visible light, your feature size is on the
| hundreds of nanometer scale.
|
| Thin films have a characteristic bending length: https://journa
| ls.aps.org/prl/abstract/10.1103/PhysRevLett.11..., and this
| determines the size of features you should pattern to exploit
| that bending/folding interaction.
| jchanimal wrote:
| I'd argue that some of the most interesting metamaterials are
| macroscale. Like radio telescope arrays or the dimples on a
| golf-ball.
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