Magnetization of antenna core - Any risks?

Hello everybody,
I got a tag installed in the usual spot a couple of months ago, and have been loving it since!

Anyway, during the last weeks of lockdown I’ve been playing with the (now nicely settled) implant and recently found out that the ferrite core in the antenna is big enough that a neodymium magnet can stick to my hand!
I saw some posts on here recommending the use of a magnet when the implant can’t be located under the skin, but I was wondering if the ferromagnetic properties of the core could be used for something else. I’m aware that ferrite is not the perfect material to make a magnet out of (so I’m not expecting it to work as a lifting or sensing magnet) but I still want to experiment, and maybe magnetize said core.
So my question is: can a magnetized core somehow stop the chip from working?
From my understanding there shouldn’t be any problems, unless the external magnet or circuit used to generate the magnetizing field started somehow oscillating at the chip’s frequency, with the field strong enough to induce a dangerous voltage (which I find unlikely hahaha). Another issue I might encounter is that a very strong field could potentially snap the core in two, but I’m very trusting in the epoxy holding everything together!
A poster on another biohacking-oriented forum mentioned his implant stopped working soon after a magnet was brought close to it, but I don’t think there was correlation between the two events.

So what do you think? Should I keep testing, or maybe try on something that’s not currently inside me? Is there something I’m missing? Thank you!

PS: I just remembered that DT’s tags can withstand the fields generated by MRI machines, so maybe my fear of snapping the core is not valid anymore… Lol

This sounds like a question for @Satur9 ( who was working 1 hour ago so probably still busy )

My input, I use a variety of high-power neodymium magnets from time to time, and I am conscious of my implants, I have had a few implant - Magnet “interactions” but I have had no issues with the operating of the implants afterward, nor have I noticed any magnetism.
From science classes many years ago, So I could be wrong here, but I think you can make ferrite magnetic but not turn it magnetic if you know what I mean.

Anyway :ringer_planet: will probably answer your question when he is free

Thank you for answering! Yes by magnetizing I meant make it magnetic, sorry about that, unfortunately english is not my mother tongue :slight_smile:
Anyway I just found out about coercivity, and I’m pretty sure the ferrite used in the implants is designed to be as “conductive” to magnetic fields as possible (that’s what makes it useful as part of the magnetic circuit, as it helps with coupling), and therefore low coercivity. Unfortunately this also means that the core won’t stay magnetized once the external field is gone.

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That’s right, good researching. You can temporarily align the domains in the ferrite core by rubbing a stronger magnet on it, but it won’t stay that way because entropy with slowly jostle the atoms back into random orientations. The only way to cause ferrite to become a permanent magnet is to heat it up and allow it to cool in the presence of a strong magnetic field. We’re talking hundreds or thousands of degrees though, so that’s not going to happen inside your body unless you’re comprised of liquid hot mag-ma.

I would recommend you not allow an x-series implant to interact with a Neodymium magnet longer than a minute for two reasons:

  1. You’ll pinch the skin between the magnet and your implant, restricting bloodflow.
  2. The ferrite core requires that coercivity you mentioned to strengthen the magnetic field being induced in the implant. If you rub a magnet on your implant and the domains become temporarily aligned, it will become detuned and the read range will reduced for a period of time.

I’ll try that now and if it works we’ll get a video.


And here we go


Very interesting, thank you for the thorough answer (and video!) :slight_smile:

I think I’ll leave the implant alone for the time being, but I’m glad that occasionally experimenting with magnets is not going to permanently brick it!

Haha, I was handling small 18650 battery spacer magnets, to achieve a solid connection in an old stacked mechanical vape mod I have, when suddenly one of them jumped on my hand. Scared the crap out of me! I clean forgot about that.

They stick pretty good. Neat trick!