9 ms·
New material that can absorb and release enormous amounts of energy
- h2odragon 5y agoAhh, but can it be made cheap enough to displace the Superball?
- mrkstu 5y agoIntersting material. More interesting to me is the Army being willing to sponsor research simultaneously with a Chinese institution...
- sybercecurity 5y agoOften 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 5y agoI 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.
- coolspot 5y agoInterestingly, in 2018 Wuhan lab applied for US DARPA grant to produce a bat coronavirus chimera. https://www.newsweek.com/darpa-denies-funding-defuse-wuhan-institute-virology-proposal-leak-drastic-1631512 https://www.newsweek.com/darpa-denies-funding-defuse-wuhan-i... https://theintercept.com/2021/09/23/coronavirus-research-grant-darpa/ https://theintercept.com/2021/09/23/coronavirus-research-gra...
- politician 5y agoI'm surprised they call it a metamaterial when the features are on the order of millimeters.
- jchanimal 5y agoI'd argue that some of the most interesting metamaterials are macroscale. Like radio telescope arrays or the dimples on a golf-ball.
- MengerSponge 5y agoThe 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://journals.aps.org/prl/abstract/10.1103/PhysRevLett.112.244301 https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.11..., and this determines the size of features you should pattern to exploit that bending/folding interaction.
- politician 5y agoThat makes sense. Thanks for the explanation.
- TTPrograms 5y agoI think in mechanical metamaterials the characteristic length defining the "metamaterial region" is rather the wavelength of pressure waves in the material you're considering - much like in electromagnetics you want the patterning (cell) length to be much less than the wavelength of radiation. In work like this they are effectively looking at 0.1 Hz or lower - near static loading - so I think pattern size can be quite large (around 600 m wavelength in bulk rubber for 0.1 Hz). This interpretation also replicates the localized behavior in the shock experiment videos. When the platform is dropped an impulse is applied with frequencies above the metamaterial regime for the material, so you see highly asymmetric response through the material - implying that the macroscopic "metamaterial" property characterization is insufficient to predict response, and so analysis must be done at feature scales rather than wavelength scales. The idea being that a "metamaterial" is a structure that can be treated as a bulk continuous material with a particular defined response as long as the interacting frequencies are all sufficiently low (far below the characteristic wavelength of the material). I think the bending analysis you cite can determine the relative feature sizes desirable for certain "micro-scale" mechanical behavior, but it's possible to build a mechanical "metamaterial" much larger than that as well.
- davedx 5y agoNo numbers whatsoever. Kind of a useless article
- sidpatil 5y agoThe actual paper: https://www.pnas.org/content/119/1/e2118161119 https://www.pnas.org/content/119/1/e2118161119
- pmayrgundter 5y agoSource pub, with some videos of the loading response: https://www.pnas.org/content/119/1/e2118161119 https://www.pnas.org/content/119/1/e2118161119
- marto1 5y agoCan 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.
- capableweb 5y agoWithout 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 5y agoThat's a good energy storage mechanism, but do you know what the efficiency is? Also, how much energy could you practically store there?
- addaon 5y agoCan't speak to efficiency, and obviously depends a lot on assumptions... but a big pool with a 40 m height difference stores about a gigajoule [1]. [1] https://www.wolframalpha.com/input?i=volume+of+an+olympic+swimming+pool+*+density+of+water+*+40+m+*+1+gravity https://www.wolframalpha.com/input?i=volume+of+an+olympic+sw...
- stavros 5y agoHmm, 278 kWh, that's great for a house, though you need a fairly tall and big water tower for that.
- mwcremer 5y agoBigger scale: https://en.m.wikipedia.org/wiki/Helms_Pumped_Storage_Plant https://en.m.wikipedia.org/wiki/Helms_Pumped_Storage_Plant
- 5y ago
- mrfusion 5y agoCan it be used for shock absorbers or seat belts?
- nprateem 5y agoIt's funded by the US army. They clearly want a material they can coat their tanks, etc with to defend against anti-tank missiles.
- stevespang 5y ago
- halpert 5y agoIt would be great if this material could help with brain damage in contact sports by making helmets better.
- abeppu 5y agoThat'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?
- MarcoZavala 5y ago
- deleted 5y ago[deleted]
- kbelder 5y agoConclusion: 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.
- deleted 5y ago[deleted]
- eointierney 5y agoHelmets 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
- vimax 5y agoReading the paper my first thought was, could this be scaled up for a a tactile touch screen display?
- henryw 5y agoCan this be made into bulletproof clothing that looks like normal clothes? That would be cool
- errcorrectcode 5y agoUHMWPE already can do that.
- petermcneeley 5y agoJoules per Kg or gtfo.
- errcorrectcode 5y agoWell not just energy capacity [J/kg = m^2/s^2 = 1/3600 W hr/kg], but power capacity [W/kg = J/(kg s) = m^2/s^3] too.
- natnatenathan 5y agoI was hoping it would be called Astrophage... ref: https://en.wikipedia.org/wiki/Project_Hail_Mary https://en.wikipedia.org/wiki/Project_Hail_Mary
- udbhavs 5y agoI was hoping for Vibranium :)
- playa1 5y agoThis is also the first thing I thought of when reading the title.
- kubami 5y agoDid you get to the horrible destruction and millions of people dying part? Not that astrophage wouldn't be cool!
- techdragon 5y agoI actually wish the book had been more about it… the post launch part of that book was honestly the least interesting writing I’ve ever read from Andy Weir. I also still can’t get over using a hand cranked winch instead of using the entire ship as a capstan while performing a barbecue roll. (Hopefully that a winch is involved is not too much of a spoiler for anyone)
- kubami 5y agoI agree! The whole progress of what must have happened as the world is pushed into "dark" ages. There is a book in there! btw. I'd recommend all the Expanse books if you're interested in how the whole civilisation manages a catastrophe.
- deleted 5y ago[deleted]
- beambot 5y agoJust 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.
- dheera 5y agoI mean, to be pendantic, mechanical storage actually is electrical storage, just not electrochemical storage :-P
- asdfman123 5y agoI find this comment repulsive
- dvsfish 5y agoelaborate?
- novaleaf 5y agohe's trying to be punny.
- neltnerb 5y agoare you positive?
- dilippkumar 5y agoI find this comment attractive.
- Nition 5y agoNot 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 5y agohttps://en.wikipedia.org/wiki/Compressed_air_car https://en.wikipedia.org/wiki/Compressed_air_car
- jiggawatts 5y agoCompressed 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 5y agoThanks, 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!
- jiggawatts 5y agoPrecisely. Any attempt to "optimise" the specific energy of a storage approach will inevitably bring it closer to closer to the point where it explosively disintegrates. This is why it's a bit hilarious to see how upset people are about lithium batteries occasionally exploding. That's... sort of the point! They've been optimised until the safety margin (=weight) is a low as possible. You want safe batteries? Carry around something the size and weight of a brick! Ditto with all possible kinetic energy recovery system (KERS) designs. You can have weight-efficient or safe, but not both.
- rkagerer 5y agoHow would it's usable energy density compare to, say, a Lithium Ion battery (or some other thing I'd be familiar with)?
- londons_explore 5y agoVery low, or they'd mention it
- errcorrectcode 5y agoWho's going to be the first to make a slingshot from this? :)
- morphle 5y agothe pdf of the actual paper: https://www.pnas.org/content/pnas/119/1/e2118161119.full.pdf https://www.pnas.org/content/pnas/119/1/e2118161119.full.pdf
- wantsanagent 5y agoThis is the comment referencing flubber that you're looking for. Flubber!
- jadbox 5y agoExactly why I came to the comments. Tbh, the "idea" of flubber is pretty futuristic. Imagine shoes that can bounce/return your running impact which could improve your speed by some real significant factor.
- telchar 5y agoI mean, springs would do that. Maybe a latch with slightly delayed release mechanism would work better to time the energy release for optimal running. But unless you want to violate conservation of energy (like flubber presumably does) then springs would get you there.
- ncmncm 5y agoThere are, in fact, such shoes, and they do provide what has been called an unfair advantage in track sports.
- sudosysgen 5y agoThat is actually already a thing, and yes they do provide a significant advantage.
- Cthulhu_ 5y agoOther people point out shoes, but there's also these contraptions that are basically springs / elastics inspired by kangaroos; I had to google a few times, but their common name seems to be "jumping stilts" [1]. There's also more compact variants, jumping boots, that look like leaf springs underneath skeeler / ice skating boots [2] [1] (no affiliation) https://www.amazon.com/Air-Trekkers-Exercise-Entertainment-Protection-Included/dp/B07P82X365 https://www.amazon.com/Air-Trekkers-Exercise-Entertainment-P... [2] https://www.amazon.com/Jumping-Shoes/s?k=Jumping+Shoes https://www.amazon.com/Jumping-Shoes/s?k=Jumping+Shoes
- Gatsky 5y agoAnyone know of a metamaterial actually being used in the real world?
- drivebycomment 5y agohttps://us.kef.com/metamaterial https://us.kef.com/metamaterial
- akkartik 5y agoIs an alloy a metamaterial?
- tiku 5y agoReplace the permanent magnets with coils and you get the fabric/stuff from the batman movie (memory cloth?)
- MR4D 5y ago> This research, which was supported by the U.S. Army Research Laboratory and the U.S. Army Research Office as well as Harbin Institute of Technology, Shenzhen (HITSZ)... I didn't expect that!