Test glass implants (non-implantable)

Amal, Kai, here’s an idea: non-implantable, el-cheapo test implants. Something that would be to bona fide RFID / NFC implants what X Field Detectors are to xLEDs: functional but constructed very cheaply and not sterile. In fact, they wouldn’t even have to be in a tube or anything. a coil and a chip in a piece of duct tape would do just fine.

I’m suggesting this because I’m in talks with yet another smartlock manufacturer, to whom I asked whether they reckoned their ware would work with a tiny glass transponder (not expecting any meaningful answer really…) and who answered, like all the others: send us one of your chips and we’ll test.

Obviously I’m not gonna mail them a real implant. But it would be nice to have inexpensive functional samples to give away.

If they were in the $10 / $15 range, I’d buy a dozen. It’s cheaper to mail a test chip to a manufacturer and know for sure whether their stuff works with implants than buying a device hoping it’d work, then ending up with an expensive paperweight.

Just an idea…


I wish that would exist. I’d love to test different cloners etc with a cheaper chip before testing it on a 50$ xEM for example.
Sending away test chips id also a very good idea!


I’ve got some ntag216’s in a 4mm diameter glass capsule.

These things are super easy to get from China, not loaded into an injector. Very cheap too. Wouldn’t implant them, but they’re the right size. You can get 2x12 easy enough.

They are really cheap. Oh wait, actually it is 134.2 kHz. But the title says 13.56 mHz. And oh wait, there’s a minimum purchase quantity on Alibaba.

Yeah, everything I’ve found on Alibaba have 13.56 MHz in the title, but in the description or photos, it says they are actually 125 kHz or 134.2 kHz.


These are NTAG 216. Problem is, we don’t need that many (it’s $62 for 40 tags).

Would be helpful if someone here can find a listing for something of a smaller pack. Or if DT can make cheaply made non-implantable glass tags.

Making “test chips” is not ideal for a few reasons, but we would gladly sacrifice a legit product to send to them for testing if you made introductions.

The 4mm size will definitely not represent 2.1mm performance and would be a red herring.

I wasn’t really thinking of making separate products. I was more thinking of you asking your supplier to keep the functional rejects (you know, the ones with a bad weld on the tube, bad epoxy fillup, cracked glass, compromised cleanliness… and/or possibly simply divert part of the production before the final installation in the glass tube - i.e. they send you incomplete products that are good enough to stick on a piece of tape to make a tester.

That way 1/ they get to valorize units that would otherwise be trashed and 2/ you could order more chips without breaking the bank and get volume discounts.

That’s if there’s interest for such test chips of course…

Cool, that! I’ll take you up on that.

First though, I need to figure out other things before asking them to put any real effort into this. Chiefly, their lock product looks like it’s designed to integrate into some sort of really expensive access control system, and I’m not sure it can work as a standalone system. No point in sending them anything if I know it won’t work for me in the first place.

Also, I’m cajoling the heck out of them, because I can tell they don’t give two shits about having silly ole me with too many questions as a customer. They clearly aim at large installations, they want to sell complete solutions, and I have the distinct feeling I’m wasting their precious time.

If all my other questions check out, I’ll bring you into the loop.

1 Like

hah well, the only rejects we get really are non-functional rejects… stuff gets put carefully into the glass with resin in a tested and working state, then sealed… sometimes the process of putting things into the resin or heat from sealing kills the flip-chip attachment to the carrier board and we end up with a dead tube… but that’s really the only failures… the laser is computer controlled as is the resin deposit… it’s basically automated.

As for the diversion of the finished antenna + chip… its super sensitive and doesn’t transport or ship well… basically there is a workstation that these are finished on and they go right into glass from that point… minimal travel. To handle them any other way would basically mean creating a product and doing a line production run of them to ensure proper handling, packaging, etc… it’s just a lot of effort that it’s much easier and less costly for us to just send samples directly to lock companies or whatever.

Right okay. It goes to show how much I know about the whole process :slight_smile:

Maybe ordering shite glass implants of similar size on Aliexpress is the way to go. I mean at the end of the day, it’s just about checking that this-or-that product wakes up and works with a certain kind of implant. It doesn’t have to be the exact same one.

I’ll see if I can score a bunch of M1ks, NTAG21x and EM4xxx on the cheap. Those 3 kinds should cover 95% of the products I’m interested in purchasing.

1 Like

Remember that shit ones may have different tolerances and may perform worse/give a manufacturer an unrealistic image.

I think @amal’s offer to send them actual ones is the only way to get a ‘real world’ example of a DT implant, even if China ones can get close.

Yes of course, but it’s enough to give an idea. It’d beat no testing at all. In any case, remember that I’d be sending a naked implant. That also performs differently from implanted ones.

Come to think of it, maybe I should mail them a sausage with the implant inside it or something :slight_smile:

1 Like

You can’t. I had to have a custom run made back in the day. Very, very hard to get. The others sure.

I previously linked a Aliexpress listing for 40 NTAG216 glass tags.

But if you don’t need that many, here’s a different listing for a single NTAG216 tag, which you can buy if all you need is one tag to send to the lock company. https://m.aliexpress.com/item/4000056553867.html

If the coil is made shittily, hopefully it at least reads. And if it does read, it should read better on a tag with a better coil.

You probably can’t mail a sausage unless it is full of preservatives, but hopefully they have a piece of meat such as a piece of chicken to test the range.

Out of curiosity, two questions:

1/ In the xLED, is the circuit a tuned tank at all - meaning coil and capacitor? You can get away with just the coil to light up a LED, so maybe you didn’t bother with the capacitor.

2/ If there’s a cap, is there any chance of changing the value at the last minute for just one implant at that workstation, to detune the tank? If it’s a guy grabbing the components in a tray and soldering them by hand, he could grab a cap from another tray at no extra cost. If it’s an automated machine, it’d cost a bundle in retooling and ordering a huge batch to make it worth it.

What I’m wondering is if it might be possible to order xLEDs tuned to different carrier frequencies, so that it might be possible to implant several of them in close quarters and light them up separately. I very much doubt it, but I figured I’d ask.

There’s no cap in there. The LED acts as the capacitor. You’d either have to have implants with different coils, different LEDs, or add caps in series. There are issues with doing that though, because the ESR of the cap and it’s effect on impedance lowers the brightness of the LED.

I imagine your use case is to have different LED implants that all turn on in response to different phone notifications or external stimuli?

No phone involved. I was thinking of either 7 xLEDs arranged in a very large 7-segment display pattern (unlikely, they’d be too close, and one or more of them is bound to shift and mess up the display) or 4 to 8 implants in line (vertical, parallel to each other, 5 mm apart) to flash a 4 to 8 bit code. Each lights up at a different frequency, and a coil nearby sends the right signal to light up one or more LED.

It’s just an idea. I’m 99.9% sure it’s not doable and it won’t happen, but there’s no harm in musing aloud :slight_smile: