Flexible NFC Implantation (with video)



  • Sorry about my lack of presence here for the last week or so.  Got very busy with other things for a bit there.

    The compression bandages did the trick with the fluid build up and everything was basically healed.  But then I did something perhaps stupid...

    Awhile back, and I'd completely forgotten about it, I'd ordered a 1" N52 neodymium cube magnet.  Let me start by saying that when you've got magnet implants, no good can come of such large magnets.  But, well, I wanted it so I bought it.  Past experience with other strong magnets makes me automatically avoid handling them directly with my left hand where the magnet implants are.  That's not to say I don't/won't handle large magnets with my left hand, but it needs to be in a more controlled way that just casual handling.  So that meant that I had the thing in my right hand for quite awhile.  I've had slightly smaller magnets corrupt data on the xNT in my left hand, but there was no harm to the chip and it rewrote fine.  None of my implants were ever adversely affected in a permanent manner by a magnetic field before.  I always considered it a risk, but not a large one.

    Well, after toying with the new 1" cube for 15 minutes or so, I did my usual thing which is to check my chip implants for any issues.  The xEM was fine, the xNT was fine, the other non-branded xNT clone was fine, and both LifeChips were fine.  Then I checked the flex tag.  It would not read.  It was like it wasn't even there.  It had worked fine probably 20 minutes before handling the magnet (I'd been unlocking my phone with it routinely).  I tried repeatedly.  The implant was dead.  An hour later, I cut it out.  Physically, the implant looks fine but it simply does not read at all now.

    So, well, there you have it.  I broke the implant with a magnetic field.  The same field had no negative effect on the five other chip implants I have and it was very close to all of them (well, except the one in my side).

    There's a small chance that the failure wasn't due to the magnetic field, but it seems ludicrous to think it failed for some other reason coincidentally at the same time that I was holding a large magnet in that hand.

    A quick note about the lidocaine thing, too, since it was being discussed above.  I don't use anesthetic because somehow I ended up with this mental need to have these things hurt.  I do not like pain at all, so don't think it is that.  I have developed a real hatred of scalpels because of the pain they cause.  It just became, for me, a part of the price for the implant.  If it didn't hurt to high heaven to implant, I wouldn't feel like I earned it.  Being able to endure it and complete the process also gives me a personal sense of accomplishment.  Another reason I don't use it is because of the focus that kind of pain brings.  You can't help but be keenly attentive to what you're doing if it's causing some genuine pain.  It also, I think, keeps me more cautious than I might otherwise be if cutting into myself was painless or nearly so.  I worry I might be too reckless as it is.  If it didn't hurt, how much further would I go?  I need for it to hurt and not just a little.  In the end, it keeps me safer.

    I do NOT encourage anyone else to forgo anesthetic.  It's not something you want to do.  Bearing unnecessary pain is not a badge of honor nor is it at all cool.  Please please please use anesthetic if you're doing anything beyond a simple injector-based implant.  And if you want to use it for injector implants, go for it!  There's a reason why doctors make use of anesthetic.  Grinders should use it, too.
  • aviin That sucks. But it's also interesting. I've never had an NFC chip die because of a magnet, then again, I've never played with magnets that large before. I may have to get one and do some tests.
  • I've got a spare one not suitable for implantation, I'll mess around with it too and see if I can get it to fail. I'll also try and test some random flex tags I had laying around too.
  • Honestly, I would like it if you guys can prove that magnets don't kill these things and it actually did just fail due to a manufacturing defect or something.  I would like to implant another one, but if they can get killed by large magnets, that will make me think twice about it.  Glass tags don't get killed by the magnets I've handled.  That 1" cube can make a glass tag in my arm dance around enough that I can feel it moving (iron core in the antenna coil is what's getting pulled by the magnet, I'm guessing) and the glass tag still works fine.
  • FWIW: Had my NFC light implanted on Saturday. Stitches come out tomorrow. It isn't the easiest design to install. No fluid buildup thankfully but am still quite swollen.
  • @aviin my thought is that it is just a coincidence that you happened to be playing around with a magnet, and that the coating likely failed. I think this because;

    1) the NTAG216 chip from NXP has a very strong overcurrent protection mechanism built in, and your magnet is not resonating at 13.56MHz, so it's really just not likely to have caused any issue.

    2) we've tested this by literally blasting an xNT up into the air with an EMP pulse from a huge capacitor bank, and it still read fine.

    3) the fluid issue and your body's attempt to reject it.

    The only possibility that the magnet could have caused damage would be if the chip was not truly an NTAG216 but a chinese knock off. Plenty of those are sensative to overcurrent... but again, there's really no logical way your magnet could induce the kind of current necessary to cause damage to any decent RFID chip by just playing with it. You'd have had to move the magnet over the implant or toward/away from it quite quickly to induce a strong enough current.
  • The chips are verified as original using the NXP public key, so no chinese knock offs.

    Once I get the chip I'll look for coating failures under the microscope, it's a possibility but we won't know until it's examined.

    Honestly, the most likely cause I can think of is that the ferrous metal antenna was pulled so strongly by the magnet that it caused a tiny break in the antenna loop, which would stop the current to the chip and it would be unresponsive. Again, just a hypothesis, I'd need to test it to be sure.
  • That's possible... probably not from the magnet, but likely from the wrenching and pushing during the installation... wow what a video! It could have decoupled the chip from the antenna, which just got worse the more he messed with it. This can usually be tested by pressing straight down on the chip from above to press it back down on to the metal antenna loop pad, making connection just enough to make it work while pressure is applied. This is one of the common issues typical PET backed inlays have and that's one way I test for this issue.
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