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Materials From Tough-as-Nails Crustacean Could Inspire Better Body Armor 144

Posted by Soulskill
from the don't-mess-with-the-little-guy dept.
carmendrahl writes "The peacock mantis shrimp, a crustacean which is neither a mantis nor a shrimp, has hammer-like clubs for smashing the shells of its prey. They're so strong that regular glass aquariums can't hold them. But what's interested researchers for some time is how the clubs stand up to all that stress. Now, a team has figured out why: the mantis shrimp club's molecular structure is set up to resist fractures. That discovery could lead to stronger and lighter car frames or body armor."
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Materials From Tough-as-Nails Crustacean Could Inspire Better Body Armor

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  • by MobyDisk (75490) on Saturday June 09, 2012 @11:44AM (#40268581) Homepage

    The peacock mantis shrimp, a crustacean which is neither a mantis nor a shrimp...

    Ok. So it is a peacock.

  • by PPH (736903) on Saturday June 09, 2012 @11:53AM (#40268639)

    No. We have already passed the point on the strength axis at which the car survives but the occupants die of internal injuries. For cars, what you need is energy absorption to decelerate the car's contents gradually. That means a body that will crumple.

    Body armor, perhaps. Here, the total energy of a typical round is not lethal if it can be spread over a large area of the body. This can be facilitated by stiff materials backed by some padding.

    • by wisnoskij (1206448) on Saturday June 09, 2012 @12:01PM (#40268701) Homepage

      In some specific situations yes, but in others the occupant is perfectly fine but did thousands of dollars of Damage to their car.
      And making a car more bullet resistant is in high demand from many sectors.

      • by paiute (550198)

        ...making a car more bullet resistant is in high demand from many sectors.

        I would be rich if I could make a bullet that was more car resistant.

    • Or make lighter cars that are just as strong.
    • by pnot (96038)

      No. We have already passed the point on the strength axis at which the car survives but the occupants die of internal injuries. For cars, what you need is energy absorption to decelerate the car's contents gradually. That means a body that will crumple.

      Not exactly. Yes, you want a crumple zone. But you don't want the human occupants to be part of that crumple zone, even if their soft, fleshy bodies might make fairly decent shock absorbers.

    • by Anonymous Coward

      Wouldn't a lighter car frame reduce the amount of kinetic energy involved in a collision? That seems like it would be a good thing to me.

      • by PPH (736903)

        The kinetic energy that will kill you is your bodies mass traveling inside of the vehicle (which just stopped suddenly) towards your dashboard.

        Lower vehicle kinetic energy might save the occupants in the other car. But this isn't important for two reasons: 1) High energy two car collisions aren't that common. Odds are higher that you'll hit a fixed obstruction, or another vehicle with a glancing blow. 2) I don't care about the people in the other vehicle.

        • by Anonymous Coward

          Perhaps the occupants of the other car would be just a tad more polite towards you and travel in a lighter one, if you weren't such an asshole.

          A lighter vehicle can also carry more cargo, before going over the limit for its class.

          • by Anonymous Coward

            > Perhaps the occupants of the other car would be just a tad more polite towards you and travel in a lighter one, if you weren't such an asshole.

            Probably not.

          • by PPH (736903)

            I doubt it. The only thing that seems to discourage MFFYs and elicit 'polite' behavior is a large (rusty) 4x4 with winch bumper and Idaho Stop bars (also known as buffalo bars in other parts of the world).

            Yeah, I know. Its not the safest vehicle. If I hit a tree, I'm dead. But then that's my own fault. If a Prius blows through a stop sign, it will absorb all the energy I'll need to walk away from that accident. Perhaps even drive away. Cargo isn't an issue with this vehicle. But frame strength is*.

            * Cars

            • by Coren22 (1625475)

              My new truck came with mounting holes in the frame for a front hitch which is then used for a winch. I imagine it is a pretty strong mounting point as it is a 4inch thick C beam of solid steel, but I could be wrong...

        • Lower weight and kinetic energy also means the car becomes more maneuverable, both in changing direction and in braking. This means you have a better chance of avoiding a collision.

    • by bitt3n (941736) on Saturday June 09, 2012 @12:32PM (#40268883)

      No. We have already passed the point on the strength axis at which the car survives but the occupants die of internal injuries. For cars, what you need is energy absorption to decelerate the car's contents gradually. That means a body that will crumple.

      Body armor, perhaps. Here, the total energy of a typical round is not lethal if it can be spread over a large area of the body. This can be facilitated by stiff materials backed by some padding.

      Seems like 'stiff materials backed by some padding' might describe the optimal car design also: an impact-absorbing outer layer (crumple zone), inside of which is an extremely hard shell to prevent debris penetrating and crushing the passenger. On impact, the passenger strapped within the inner shell decelerates by crumpling the outer layer, without the inner layer's being breached by debris, or the passenger's needing to decelerate within the context of the inner layer. In such a model, you would want to make the inner shell as hard as possible. You might even be able to make an even flimsier outer layer if you could make the inner layer harder, resulting in less abrupt deceleration when using harder material.

    • by willy_me (212994)

      No. We have already passed the point on the strength axis at which the car survives but the occupants die of internal injuries.

      That's not the point. Stronger materials can make a stronger frame but they can also be used to make a *less heavy frame. The goal is lower fuel consumption and greater interior space.

      *less heavy: most new materials will be less heavy as they will be primarily based on elements less dense then iron.

    • by v1 (525388)

      I think some people would prefer a broken arm over a totalled car. And it certainly is annoying to hit a pole at 8mph and instead of bouncing off, it "eats" the pole and does $2000 in damage to the car.

      • Re: (Score:2, Insightful)

        by Anonymous Coward

        And that's because the cost of a broken arm is externalized to other agents, so it appears to be less costly than the car damage.
        Even so, why value a thing over your own health?

      • maybe; but those people already have concussion from their previous accident

      • by hiryuu (125210)

        I think some people would prefer a broken arm over a totalled car.

        Give me the completely-trashed car over an injury any day; anybody who prefers the broken arm either hasn't considered or isn't aware of the long-term impact to their body and its functionality, resiliency, etc. I'd rather not have the loss of structural integrity of the bone, joint and/or muscle damage, possible need for physical therapy to regain strength and loss of range of motion, and all that.

      • In Canada we have 5mph bumpers as a "Canadian Motor Vehicle Safety Standard". The idea there is that the car should not be damaged in a 5mph collision with a solid object. The bumper should absorb the impact but stay in tact. The bumpers are usually solid and have shock absorbers, designed such that permenant damage should not occur. It is often used as a playing card by car manufacturers to prevent us from buying cheaper used American cars and bringing them across the boarder, but I would imagine if you da

        • But in Canada we aslo have free* health care... so a broken arm is less of a big deal then a 7000aed broken arm in UAE.

        • by Coren22 (1625475)

          The US has the same standard...but the bumper is generally under a cheesy plastic cover that shatters on impact...

    • by rthille (8526)

      You make the material stronger, so you can use less of it, so the car is lighter, so you can use even less material and energy to move it around.

    • by trout007 (975317) on Saturday June 09, 2012 @04:34PM (#40270153)

      Ok time for a mechanical engineer to step in here. There is some confusion between stiffness and strength. These are two different properties of the material.

      Stiffness is the ability of the material to resist deflection. Think of identically shaped tube held fixed in one end made from different materials. Now put a force on the other end and assume it is small enough so you don't bend the tube permanently. All aluminum tubes will deflect about 3 times that of all steel tubes. It doesn't matter what kind of aluminum or steel. This is due to a property called Modulus of elasticity.

      Now when we talk strength of metals we have two types. The first is yield strength. In the above example this would tell you what load the tube could take before it bends to the point when you remove the load it doesn't return to its original shape. The next is ultimate strength. This is the load when the tune actually breaks.

      These strengths vary widely for metals with some aluminums stronger than steels and the other way around.

      The next thing is density. Aluminum is 1/3 the density of steel. But you need more if it to make a stiff structure.

      So what does this mean for impacts in cars? You want a material that is stiff for its weight so that it can absorb the energy as it deflects but also strong so that it doesn't break as it deflects. Ideally you would want your car to crush like modern cars do to absorb the impact then return to their original shape so there is no damage.

      • by PPH (736903)

        OK, so where does that place this crustacean's club/claw/whatever in terms of stiffness and strength?

        I think its a combination of both. You want to have something that's strong (high yield strength) and stiff (deforms less than your target so as to transfer more energy to it).

        Either way, the design philosophy behind the crustacean's club seems to be different than that of autos in a collision. The crustacean doesn't want to bend or break its club whereas cars are supposed to crumple (exceed ultimate stren

        • by trout007 (975317)

          It was behind a pay wall so I didn't see the data. I'm pretty sure steel is both stronger and stiffer than this crustacean.

          • They don't really say. They never describe strength in a classical mechanical engineering fashion. Mostly TFA is about the microstructure of the material:

            Our studies show that the stomatopod dactyl club represents a notable departure from previously studied damage-tolerant biological composites, in that it is specifically employed for high-velocity offensive strikes. Our structural investigations, coupled with nanomechanical characterization and finite element simulations, have shown that the club consists of several microstructural features that permit the infliction of crippling impacts while simultaneously minimizing internal damage within the club. These characteristics include a pitch-graded helicoidal architecture constructed from mineralized chitin fibers that can dissipate the energy released by propagating microcracks; an oscillating elastic modulus that provides further shielding against catastrophic crack propagation; a modulus mismatch in the impact region that acts as a crack deflector near the impact surface; and an ultrahard outer layer correlated with a high level of mineralization and a radial organization of apatitic crystallites. The structural lessons gained from the study of this multiphase biological composite could thus provide important design insights into the fabrication of tough ceramic/organic hybrid materials in structural applications where components are subjected to intense repetitive loading.

            I hate it when Slashdot covers stuff behind paywalls, but unfortunately virtually all decent science and engineering is either 1) described by the breathless university PR department which could not describe the difference between gravity and fish farming or 2) behind a paywall.

        • Actually, those crustacean are cool, saw a documentry on them. Their club is actually like an elastic/spring - that is how it generates the force it uses to wind up the club.

  • ...tell the military that your science project has military applications. Otherwise, good luck getting a grant.
  • about animal lovers, is that the world, naturally, is a place of violence

    although, what it isn't a place of, is cruelty. nature kills for hunger, and with no emotion. taking delight in another's suffering is the problem. the mechanics of the violence we are born and live in and die in is without cruelty, it just is

    you see something like this shrimp, and you think: isn't this evil? and the answer is, no, because it is only hungry, it is not cruel. it is the human mind that perceives cruelty where there is no

    • by Anonymous Coward

      Well, cats domestic and big cats tend to kill anything that moves and not just to eat.... do they find pleasure in it I don't know, they do seem to have fun with it from having watched them with lizards.... should I have jumped up and stopped that, I don't know.... I wonder why we only sell cat food in flavors people would find interesting, I never see, rat, snake, lizard on the shelf, but my cat seemed to like snake more then anything else.

      • For cats, playing with food is a form of training exercise. The mother cat brings dead or half-dead prey to the kittens so they can practice hunting.
        • by Smauler (915644)

          Not true. I've seen plenty of adult cats playing with smaller animals, then killing them, just for the fun of it.

          Also, there are killer whales - they play with sea lions a lot, throwing them in the air, etc, before they eat them. They also kill stuff they do not eat, too.

      • I wonder why we only sell cat food in flavors people would find interesting, I never see, rat, snake, lizard on the shelf...

        Cats don't buy cat food. People do. It's the same reason fishing lures are all fluorescent and sparkly, instead of organic looking. They are marketted at fishermen, not fish.

        • But I think it's been proven fish love to try and stick sparly moving things in their mouth. The spinner is really effective. Often more effective then a plan old organic looking grub.

    • by Sodki (621717)
      There are some nutty "animal lovers" out there, but I think most of those that are against easting meat do it in protest against the cruelty of how animals are raised for human consumption. As a meat-eater myself, I often think about this and I'm getting closer to be an almost full-time vegetarian. I don't have any problems eating the livestock that my parents raise, because I know they live a good life, full of great outdoors, and are treated with respect. But I've seen my share of farms and in some of th
    • although, what it isn't a place of, is cruelty.

      That's good that you don't allow mammals into your "nature". Those are creepy creatures.

  • Everything I know about Mantis Shrimps comes from The Science of Discworld (a book which should really be named, The Science of Roundworld, since it's about how the inhabitants of Discworld might view our world), by Terry Pratchett and two scientists, one of whom actually owned one of these critters. They're extremely smart (relatively speaking). He used to set it puzzles it had to solve to get food. After a while, it started ignoring food that didn't involve solving a puzzle, apparently because it was t

  • by Arancaytar (966377) <arancaytar.ilyaran@gmail.com> on Saturday June 09, 2012 @12:21PM (#40268823) Homepage

    The very point of a car frame is to crumple. They're expensive to replace, but not as much as the driver.

    • by Fnord666 (889225)

      [Car frames] are expensive to replace, but not as much as the driver.

      Not really, but people tend to frown when you put things in the opposite order.

      • Bahhahaha

        "What happened to Jimmy?"
        "He got in a fatal accident so we replaced him with Lin Sung here instead. He's adapting quite well to our culture but Jimmy's old wife still has some reservation"

    • by vakuona (788200)

      No, parts of a car should crumple in a controlled way. You do not want the passenger section crumpling. You use airbag to absorb energy in those parts.

      • An air bag is not a pillow. It is unable to surround you in that split second with a nice soft place to park your face. You are still belted into your seat. The passenger section should collapse too(slightly) if the alternative is that the occupants aren't going to survive. Take for instance a hit to the passenger door - there is not much crumple room no protection from side to side whiplash - I'd rather have my passenger pushed towards me then us both dead.

  • If it's as tough as nails, then why not just make the armor out of nails? Thanks folks, I'll be here all week!

    • by Chrontius (654879)
      But four-inch-thick hardened steel similar to nails is used in armor. Just not the kind you wear.
  • ... in the process.

    This is neither the first nor in any way exceptional, but in every single instance, it is a disgrace!

  • Does this protect against it? Never know when you might be fighting Xenomorphs.

  • Paid Subscription (Score:2, Insightful)

    by Anonymous Coward

    Kinda worthless linking an article the requires a paid subscription to access.

  • What we've got (Score:5, Informative)

    by sco08y (615665) on Saturday June 09, 2012 @02:26PM (#40269473)

    Just to outline what the standard gear can do as of fairly recently; I'm out, but I wore it in 2010.

    The kevlar lining in the vest, by itself, is rated to stop 9mm pistol rounds.

    The main chest and back ESAPI plates are rated to stop a NATO 7.62x51 round. (The AK commonly fires the lighter 7.62x39 round.)

    The armor is bulky as hell. The full assemblage, helmet, shoulder protectors, front and back plates, side plates, etc., is heavy and greatly restricts movement. I found it very difficult, with everything on, to man a gun and drop down to check radios. (I've also never found a decent pair of gloves.) I stopped wearing the neck protection and shoulder protection while driving because I couldn't easily turn my head.

    The problem of being trapped is partially addressed through the quick-release mechanism; there is a strap you pull that will simply make your armor fall off. Of course, there's a fairly elaborate system of cables wound throughout the armor, and the armor itself is more annoying to put on.

    My feelings are that we're well past the point where the increased likelihood of getting shot while stumbling around is worse than the benefits of not getting hurt by shrapnel. I'm considering a common combined IED and small arms attack in which the convoy is successfully stopped, and they have to kick out dismounts to respond. In that scenario, getting in and out of vehicles is very dangerous (especially some MRAPs where you have to basically go out ass-first) and performing tricky tasks like hooking up tow bars and tow cables.

    The next biggest problem is it's hard to allow air flow. The armor tries, and they recently came out (thank god) with a lighter shirt to wear underneath it instead of the regular ACU top. That was a huge improvement, but it's fundamentally hard to put yourself inside a ceramic box and not cook.

    Except for shoulders (and no one wants to wear the damned shoulder armor) it doesn't protect joints. The neck protection further restricts mobility.

    Wearing it, overall, I felt like a damned turtle. Other people I saw didn't seem to be doing much better.

    • Well, we simply should invade Canada and stop bothering with the pesky, hot, dangerous places.

      Mosquito repellent and you're golden!

      • by sco08y (615665)

        Well, we simply should invade Canada and stop bothering with the pesky, hot, dangerous places.

        Mosquito repellent and you're golden!

        No, fuck no. Too goddamned cold.

        Why not invade Italy? Or take over a few more tropical islands?

    • by drinkypoo (153816)

      Too bad they won't let you have dragonskin. Instead, the guy who oversaw the "competition" now works for the company that makes that armor you wore.

      • by Chrontius (654879)
        Dragonskin was even heavier than the Interceptor, and while it offered much better coverage, the junction between the scales could be blown straight through by an AK, if it hit at just the right angle. However, it was a lot more flexible.

        The Army didn't think the weight penalty was worth it, but some soldiers disagreed.

        And when it was Dragonskin or PASGT, the Dragonskin vest won hands-down. PASGT was roughly equivalent to NIJ level 2A, (rated for light sidearms) but Interceptor is somewhere around N
      • by sco08y (615665)

        I'd have to wear Dragonskin to make any judgement. I've heard it was even heavier... heavier armor means you carry less bullets and water. For convoys, Dragonskin probably would have been great since you are in a vehicle. Not so sure about foot patrols.

        The biggest problem the Army had wasn't favoritism towards this contractor or that. The biggest problem was entrenched bureaucracy, the CIF structure (central issuance facility) could not get gear to soldiers. Incredibly, CIF wasn't simply fired for not doing

  • by pittance (78536) on Saturday June 09, 2012 @02:33PM (#40269517) Homepage

    Lots of natural materials exhibit really interesting properties, sometimes at odds with the way we'd expect such materials to react. For example crustacean shells are ceramic but quite tough because of the layering of the ceramic with small amounts of organic binder material which causes any fractures to be diverted before they spread though the bulk of the material.

    Many natural materials exhibit high levels of hierarchy like this and it's one of the many reasons why natural structures and materials are way cooler than most of the things that we make, with the possible exception of aerogel. One of the most interesting hierarchical structures is Euplectella Aspergillum (Venus' flower basket [wikipedia.org]), its structure is really complex [nhm.ac.uk]. I can easily see this being an aerospace material in 10 years...

  • by Anonymous Coward

    The way the fibers are laid out to create the surface can have a dramatic effect on it's strength and ability to maintain shape. Watch this TED talk [youtube.com] for more interesting facts about penis anatomy.

  • by IonOtter (629215) on Saturday June 09, 2012 @10:16PM (#40271785) Homepage

    ...is it's primary hitting power is not the claw itself, but the inertial cavitation shockwave. [wikipedia.org]

    The creature lashes out so fast and powerful, that the impact generates a cavitation bubble on the forward surface of the claw. [wikipedia.org] So not only does the claw hammer in, but there's a nasty blast of energy as the cavitation bubble collapse at the speed of sound. Its so powerful, it even generates light! [youtu.be]

  • Layered composite materials. People who have been designing and building fault tolerant systems have been using such techniques for a very long time.

    It may be interesting to determine that's what's at work in this instance, but it's not a new technology.

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