Subdermal Armor



  • Ok so lets deal with this in reverse order.

    My use of ballistics gel doesn't mean I don't know what I'm doing it means that writing our ballistics gelatine is slower and short forms are common. Also not all ballistics gel is gelatin based so your conjecture is meaningless. The FBI and various others use a clear synthetic gel that has zero gelatin in it and as such referring to it as gelatin would be both meaningless and stupid. 

    Well designed implants are not hard to get right, that's why they're well designed. Those rejections are almost entirely from people being unable to preform proper sterilization/implant/aftercare procedures. And those are hard pieces of rock essentially in soft squishy bits. Implants that get put in in hospitals do not reject nearly as often as those magnets do. So no a well designed implant that's put in properly shouldn't be the issue. Besides, the whole point of testing this is finding out how it holds up.

    I've been looking into armour design for years. again your conjecture that one "some fabric from china" in't going to stop anything is largely irrelevant. First off the reason we're looking into this material is because it was brought to our attention as having close to the same mechanical properties as kevlar while also being very biosafe. Hence the testing. We're not skipping to the bit where we shoot someone. We're starting with a cheap version to see what happen against actual stress tests. If it turns out to be crap, we move on. Some materials have a fair bit of sheer thickening capabilities so a very thin layer layer can actually block all of the various impacts. There are some body armours in development that are no heavier than a tshirt but can quite happily take the abuse from knives and bullets. Take for example boron carbide fabric dipped in shear thickening fluid made of silicon nanoparticles. The stuff out preforms all current body armour. So we test this stuff to see how it holds up to all this. The reason we embed it a little ways into the gel is to see how it'll move around on impact and the damage to lower tissues. If we see that it's viable and has some stopping power then we move forward. 

    Obviously the stuff from china will be low quality. That's a given. The point of it s to see what a low grade material can do and if it preforms well then it's a very good indication that higher grade stuff can as well. It it preforms poorly then we can try again with better stuff and if that sucks too we move on to a different material.
  • I may have worded part of my proposal for testing protocols incorrectly. When I said that there would be a pool of people performing each test, I meant that the pool would be wielding the weapons, not serving as the targets. 

    Obviously the structure of the implant is still up for debate, but I think we will also need to take into is the way that the tissue will integrate with the implant. I wonder what the effects of coating the fabric in the HA compound that @glims is using for the flash drive transdermal implant. That could provide us with the necessary "anchoring" for such an implant to be effective. And unless someone basically wants to have an extensive number of surgeries over a number of years (Or months if they're really gutsy), regional implanting is really the only the way to go.

    True enough, without a shear thickening fluid, I wouldn't bet on a fabric of any sort stopping a stab attack with an ice pick, stilletto, or other knife(Even though there have been ultra-tight weave Aramid fiber vests rated as stab proof, so maybe if the properties of a fabric with this kind of weave are favorable, we can use some for our implant). In addition to lacerations and abrasions, I think it could certainly have an influence on the severity of incised wounds and penetrating, wide-area wounds, like a shotgun firing birdshot. 

    If we're looking for ballistics-vest quality, I believe I posted a source with UHMW-PE weave designed for use in ballistic vests. and if worst comes to worst, we can just buy a large quantity of UHMW-PE "thread" and weave our own fabric.

    In terms of tissue damage under the implants, post-wound-infliction, a similar issue has to be dealt with when designing ballistic vests. It's referred to as the backface signature, and describe how much kinetic energy is transferred to the wearer over a specific area. We'll definitely have to take this into account.

    In regards to material quality, I found a number of companies in the U.S. that will convert solid blocks of UHMW-PE into thread and other forms, so as long as we can source that, we can make whatever quality fabric we want. 
  • A quick tip for sourcing this stuff. It also goes by the names of Spectra(TM) and Dyneema(TM). There's usually considerably more UHMW-PE Fabric going by those names. 

    They appear to be high quality, and U.S. Based, but will likely be extremely expensive.
  • I wonder how tissue with interact with this stuff tbh. I think it would be interesting to impregnate the stuff with something like fibrinogen like we're using for the transdermal and see if the tissues will stick to it. That would certainly add stability to the thing. As to stopping power I feel that maybe thin tight woven layers may be the best after all. If we got some of the thread we could sew the layers together in places such that they won't slid around but will still provide the added protection of multiple layers. If each layer is thin then the whole package will stay thin. and that way the knife or w.e we use will have to go through more layers which is far more difficult. a good kevlar vest usually has upwards of 12 layers of very very fine fabric, we could probably go up to 4 or 5 before we lose the flexibility and this becomes useless again. Since past a point you may as well have plates under your skin, which would be uncomfortable to say the least. As to how to implant I feel an unrolling of the material subdermally would work to cover the most area. Make a smallish incision then use probes to detach gently the dermis from the subcutaneous tissue. Once a large pocket is made stick the tube of fabric in and unroll it to fill the pocket. Sort of how they do the sub dermal silicon implants. I still think the cheap stuff is best for an initial test. No sense shelling out for the expensive stuff just to fuck it up. Lets see what low quality can handle and scale up.
  • edited May 2015
    I think you could have a twill woven fabric for cut resistance with an impact-resistant sheet underneath. You could use a chitosan yarn to ladder stitch both layers under your skin. As for hydrophilic or anti-inflammatory coatings, they wont be effective for long periods of time unless you immobilize the substance to the surface, which are tedious processes and not worth it, since polyurethanes are already pretty bio and hemocompatible. For instance, if you wanted to bind heparin, you would need ammonia, heparin, and coupling reagents. You would plasma treat the polymers in ammonia, and then use the reagents to bind the heparin. Maybe you could vacuumize a microwave, but it would still be dangerous because of UV radiation. Fibrinogen can help initially in the healing process. When it comes to implants, you don't want sustained clot formation, because it induces inflammation and encourages fibrosis.
  • I suggested using HA because I'm presuming that it has a tendency to bond the tissue directly to the implant it's coating, which would improve the stability of the implant, so to speak. Unless UHMW-PE already has a penchant for bonding to tissue, the tissue's only going to grow around, over, and through the holes in the implant, sort of like pressure-fitting a pipe. But, if you introduce "glue" into the "pipe-fitting" procedure, and get some nice chemical bonding between the various materials, the strength of the connection will be significantly greater, and you won't have to worry about things moving around. 

    If we're worried about having to plasma-treat something without going to the professionals, converting a microwave into a vacuum-chamber plasma generator doesn't seem terribly difficult. If UV radiation is an issue, an easy fix is building a large box around the device out of a material opaque to UV rays (With the requisite door), and simply closing it up while it does its thing, but I digress. 
    That stitching idea seems interesting, though it'd really really really suck if the thing rejected. Would you be stitching just the 2 layers of materials together? Or stitching the skin and the 2 layers together from the surface?
  • Can't use HA. requires a ton of heat to coat the material and the plastic would melt or burn. Also the material needs to be conductive to coat well with most methods. Same reason we can't plasma coat things. Very few plasmas are cold enough to not burn the stuff and the cold ones aren't usually good for coatings.
  • no one wants to do this? well that sucks.

    earlier in this thread we mentioned titanium reinforcements, looks like some people are already doing that. 
  • We kinda concluded that there wasn't any good use case and no real established path to move forward on...
  • I'll pursue this in the background, with whatever money I have leftover (Heh. Who knows if/when I'll ever have any), but only because I'm really jonesing to get some of that Deus Ex-styled Dermal Armor.
  • I'm still working on this but money isn't being spent on it at this time
    if i had cash to spare for this project I'd run with it faster.
    Also I still think the plastic mesh was the best we've come up with
  • @AlexSmith the titanium implants you mention are more for striking than for armour purposes. While you could posit that they may be useful for support, an attack would ignore the implant completely, as you usually go for the meat.

    However, maybe there should be more discussion on support system (bone) reinforcement.
  • That's what I was kind of thinking as well when I saw this thread. Say for example implanting titanium plates under the skin of the knuckles will function like an irremovable knuckle-duster. 

    I feel that going about having sub-dermal armour in the body is going about this the wrong way: having armour in the limbs not only can defend (by parrying stuff) but also offend.
  • edited May 2015
    I like Ivo's thinking. One thing I would love to have is transdermal, bone implanted threaded sockets in the knuckles. It was in some book I read, sometime. Depending on the accessories, it could be both a small defence weapon or an effective offensive weapon.

    Hardly 'Subdermal Armour' though.
  • Same concern they raised in Eldest, where you probably picked that up. You don't have dwarf knucks, yours are pretty small and complex joints. Difficult to fit a proper well there and not screw everything.
  • You don't have to fit a well at the knuckles. All you need is subdermal plates on the surface that forms the front of your fist. Maybe you might need to reinforce the bones forming your palm too (the metacarpals).

    Also, not that it doesn't have to reinforce the fist: knuckle dusters (and boxing gloves to a degree) work by giving the fist more mass so that you can hit harder.
  • Cheers @ElectricFeel - I thought it was in the Eragon series. And yeah, that was my concern - not really any way around flimsy bones.
  • Joints aren't a great place to work for a number of reasons. Id be interested in plates over the ulna and radius but wouldn't work on someone's joints. Id likely be willing to do the wet work on such a project. Let me know.
  • I'd definitely be interested in having it done - living in Australia makes it difficult for me to take up your offer though.
  • How would you do pain management for something of that scale? Do you have general anesthesia capabilities?
  • depends how big. If we're doing your whole chest then ya general would be good. for a smaller piece like a forearm could probably get away with lido
  • General anesthesia is totally out of the question. I could see someone doing conscious sedation but I sure as hell wouldn't get involved. Even large regional anesthesia can be rather risky. Subdermal stuff in general wouldn't require much more than local infiltration or a nerve block.
  • Unless someone happens to be an anesthesiologist, willing to put their career on the line for the project, and in posession of all of the necessary equipment and chemicals.
  • give it a couple years. sooner or later someone will build a facility where this could be done. all in good time.
  • Yeah, building a facility is definitely a long term goal. land in Mexico is cheap...
  • Or alternative we can start small and put subdermal plates under the proximal phalanges except for the thumb. :P
  • What about instead of using plates, you 'wove' some strong, safe-for-the-body threads into the lower layers of the skin? I bet you could even use a suture for it. That'd reinforce your skin while maintaining a good level of flexibility, right?
  • @otptheperson has a good idea, I think. There are certain weaving patterns that are damned strong too. It would definitely need to be masterminded to avoid tourniqueting.

    Did anyone have this idea yet?

    Like ringmail...kinda.
  • I've been sourcing a bunch of stuff through some Chinese med companies. I found some really cool titanium mesh for implant that could be used. Wouldn't help with impact but should prevent some cutting. I'm intrigued by some of the osteointegrating pastes and coral stuff. I'm trying to find out if contact is needed with periosteum or what. Technique questions basically.
  • Argh! I had some of that titanium mesh stuff sitting around my garage since last year. I just went to find it for you but I guess it got thrown out. It was surprisingly stiff stuff.
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