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Materials From Tough-as-Nails Crustacean Could Inspire Better Body Armor
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."
The peacock mantis shrimp, a crustacean which is neither a mantis nor a shrimp...
Ok. So it is a peacock.
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.
Have gnu, will travel.
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 them the conditions in which animals live are horrendous. This is the cruelty you speak of.
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.
The very point of a car frame is to crumple. They're expensive to replace, but not as much as the driver.
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Kinda worthless linking an article the requires a paid subscription to access.
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.
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), its structure is really complex. I can easily see this being an aerospace material in 10 years...
...is it's primary hitting power is not the claw itself, but the inertial cavitation shockwave.
The creature lashes out so fast and powerful, that the impact generates a cavitation bubble on the forward surface of the claw. 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!
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