Transdermal: Why it doesn't work, how we can make it work.



  • We already have a material that allows the skin to fuse to the implant and close the gap. We're in the process of testing it but if you can find other materials by all means. But from what I could tell vetigel won't work. But feel free to prove me wrong. There's a small peptide that has shown some sucess but the hard part is binding it the surface of the implant in a way that keeps it functional. So ya there's a few materials out there and you've got the right idea. You need a material that the body THINKS is a more body and give it something to physically attach to.
  • @glims basically zeno's paradox. there's always an edge. too bad we can't anchor directly to bone... titanium mesh and some 3d printable materials(high tech labware, not home grown repraps) are used to influence and support bone growth, if we had a way to grow the bone around our transdermal, say a usb port, but made sure it didn't cover anything it shouldn't have... idk. just spitballing
  • We're not using a plant extract. We're using a purified human extract (lab grade, not home made). The _theory_ is that the skin will actually grow onto the coating which is bonded to the implant.  The skin barrier is always the issue. Technically, there isn't always an edge. There are lots of situations where this is true in nature. What were are going for is more like a transition state. We'll see how it goes....
  • edited October 2015
    Ok here are the first pics of our first prototype shell. It's for testing purposes only, just testing the strength of the coating. It's coated in a 20nm layer of gold. I'll be stuffing it into a bit of chicken and whacking it around to see how the coating holds up. I'm still working on a better coating but this lets us at least move forward a little. 
  • I feel like for some reason that it should clarified that this is just a coating test. obviously that classy crimped end is not a final thing. Y'all remember that hideous block that I had in my arm a few months ago? This is the house for that.
  • Could someone pist a link to that "hideous block".
  • Oh and update on this gold coating. It's too thin and didn't adhere. Ish came off when force was applied. Gold no good. Using titanium.
  • @chironex is swamped with school. So, it's me again. HA coating has been applied on top of titanium. Voltage was too high, so it looked like synthetic coral. Which is cool, but not what anyone is looking for in this case. Waiting on some chemicals to reduce cost of process, adjusting voltage, etc.

    There's kind of a self imposed deadline (jan1) on this so expect it to take as long as it takes, but not to take forever.
  • To be fair, I'd be interested in seeing what the too-high-voltage results looked like, not to mention rundown of it's physical properties.
  • Same. Unless it detracts from other more pressing matters. At least a picture would be cool, if you have one.
  • It looks like coral. Like foamed rock.
    He's off trying to make it into a paint now...
  • edited December 2015 I posted a whole video going through the process. also it's less porous in the coral sense and more in the "the titanium was eaten away by the voltage" sense. Now working on a silica-HA composite so we could just paint on a layer instead of the electrodeposition. almost got it working too. The layer is a bit flakey atm so gonna try heating it to a couple hundred (800~) degrees to really melt it on there.

    totally dry 

    When mostly dry:

  • I got the paint working properly. I screwed up the coating cause it got too thick before i'd coated it all so I only managed to properly coat portion. The coating is hard as a rock. Hit it with a hammer and it didn't budge. Sanded off the surface to expose the HA. It looks rough but it's actually super smooth and I can sand it with 1000 grit and it just gets shiny. I need to make a better more pure and clean batch of HA and then mill it with the sodium silicate so there's less specaling and a more uniform coat. That said the HA particles are pretty small so even areas that look grey are actually full of HA. I may give it a further treatment after coating to make it more hospitable to the host. Eitherway this is a really cool paint. 
  • Finally think i've got this finished. It still needs a little bit of work but thus far all is going well. 

    Roughed with 60 grit for better adhesion of coating

    Fresh after painting, rough and bumpy.

    Dry but not polished

    Polished and almost done


    under a scope 


    Flat face of coating, you can see all the bits of HA 
  • I'm terrified. And excited.
    Hows the internals looking. Or are we, at this point, building an arm cave. I'm ok with arm cave, I'm just clarifying.

    Also, before anyone else says it. Those edges look brutal
  • Picking up parts for internals today. The whole thing should be finished by end of day. Fixed edges. There are a few small crack cause of how it dried so gomma give it a spray with dilute silicate to fill any and then sand it smooth again.
  • It is possible to have the picture made smaller to be albe to see the full ? I see them huge 
  • Try refreshing the page.
  • @ChilliEye nope still huge. 
  • right click and choose view image in new tab. will show a smaller one. i  dunno why the expand like that. probably a relic of the sites construction.

  • There are a few things I would like to change about this sites layout... Anyways how did you make and apply the HA coating? I have come up with a way to "cheat" on my SAT and I need to implant a computer in my neck or under my rib. See the implantable Edison project for ware I am going with this.
  • Um.... good luck with that? 

    I did some more tests on the coating. When heated with a small butane torch the coating puffs up by 1-2mm. It becomes brittle and can be scraped with your nail. It doesn't come off, but some of the puffy silica breaks as you scratch it and powders off. More heating doesn't increase this. Autoclaving is a no-no. the humidity and heat cause the metal to heat so the silica puffs up at the interface between the implant and the metal so when you scratch it it come off. I tried soaking it in ISO and it came out fine so it'll be sterilized that way (or more likely with chlorhex. point is the coating isn't soluable). 
  • edited December 2015
    You're going to need to soak it in some blood temp saline to make sure it's ok.

    Or, yknow, just a vat of warm blood.
  • Well this is gonna make for an awkward conversation with my roommate "don't worry it's not THAT big of a syringe, I only need a cup or two"
  • Fully assembled and coated. Just needs the PDMS fill 


    Test fit before final assembly. 
  • Chip was fried from all the handling and abuse i put it trhough the last few days. new one is on order and will attempt again. Now i've got the basics sorted hopefully will be a quick fix in a few days.
  • What are you putting in there exactly? Is it just a little flash drive?
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