Short range but wide area antenna design?

Hmm well, to be more specific, what I meant to ask you was: do you think the FlexEM would be too stiff in a soft and floppy skin area on which I sleep for hours every day? Would the implant risk cutting into the flesh from the inside with the pressure and movements during sleep or something?

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Yeah it’s a rigid disc. Zero flex. How it feels is totally dependant on your “floppy tissue” :wink: My hunch is that there will not be a lot of tension and that’s the biggest risk. I’d guess that the lower cheek just above the thigh and below the butt crease would be a good spot because I can’t imagine a movement that would cause a lot of tension.

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Ok thanks. I think I’m gonna give it a pass: even if it’s safe and it won’t hurt me - and that’s a pretty big if - I’m afraid it might create a nasty feeling in my backside when I’m in bed.

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Would likely have similar concerns but what about the upper back. Would depend on chair design but could work.

Small update on the long range readers: I tried them again yesterday evening at home, as far away from metal bits as possible, and it makes a world of difference in terms of reading range. At the office where I had first tried them, there was metal strips under my desk - about an inch behind the reader. That seems to be enough to kill the range.

So, placement seems to be critical. But if you get it right, it can be pretty effective.

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If you could find a good spot under your desk would thigh or calf placement be an option?

Yeah that’s an option - or on my hip, with the reader on the side of the char. The thing that makes me want to put implant the chip in my behind (or very close) is, I sit on it. So gravity would endure the minimum distance between the chip and the reader.

Also, if it works, I’ll install the second reader under the couch, to turn on all the electrical appliances in my living room automatically when I lounge on it :slight_smile: I couldn’t do that with the chip in the front of my thigh.

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Well, after almost a month of waiting, I finally got the thing in the mail and installed it at my desk at work. I have to say, it’s pretty awesome. It locks the session as soon as I get out of my chair, and wakes up the screensaver as soon as I come back, without fail. I don’t even need my overly-complicated screensaver killer trick no more.

It’s a very old product though: the configuration utility doesn’t know anything beyond Windows 2000. But it still works fine, so no problem there.

I still need to present my hand to the reader to log in, but at least Windows is all woken up and waiting for me to do so, so I don’t have to do wake it up manually. Now if only my piercer would reopen his parlor so I can get that transponder implanted in my rear-end. Damn virus…

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If it ain’t broke…

I think that will complete it, ultrasound wakes it just in time to sit and sign in. For sure beats the AnusID™

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Yeah but that’s the thing: I don’t want to sign in - at least, I don’t want to have to do it manually by showing my hand to the reader. I want to be authenticated by sitting down.

So yeah, the sonar thing is nice to automatically lock the session, but it alone doesn’t solve the log-back-in part.

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Augment one of these. NXqnaAz

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How about this guy? With the edges sandblasted or otherwise rounded off, so they don’t cut into your biopolymer coating later on, it might work. What do you think? Care to quote me for an implantable one of those?

I doubt it actually… this looks like a ceramic resonator which is very thick. I was thinking more about inlays. Super flat, thin, flexible uhf tags… I can easily convert those.

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This one caught my eye as very implantable:

https://www.dipolerfid.com/RFID-Tags/smartrac-trap-nf

Okay I thought you could safely encapsulate anything of any thickness, provided the would-be implantee is okay with implanting it.

Right, back to the search engine then :slight_smile: Maybe Leumas95’s find would work… But I want more information first. Of course Amal, if you yourself are already eyeing something that would be suitable, don’t hesistate: all I’m doing is googling around without any real clue as to what’s suitable or not…

Yeah I have not tested them, just size wise it seemed decent.

The manufacturer won’t say anything about read range (wisely, probably). I’d like to find out what range I can expect “ideally”: if it’s 5 inches, it’ll likely be 1 when it’s implanted, so there wouldn’t be any real point.

Interesting video of a guy testing the read range with a UHF bird ring tag, first alone, then wearing it around his finger: in the second test, the range is dramatically reduced:

I’m tempted to order a reader and a tag, and try to read it with it inside my mouth. Then possibly swallow it and see if it still reads at all. A small tag obviously :slight_smile:

Yeah… Die-cut Size: 11 x 25 mm … the implant would be 13 x 27ish. Not awesome but not bad.

This is the biggest issue. You can see this effect on UHF badges… wearing as they lay on your chest the range is reduced by about 80% … this is why schools that have these badges for kids must put uhf panel antennas directly over the door facing both directions so they are sure to get a 90% read rate on tags passing through… while if the badge was simply held out from the chest by about 12 inches (about a full wavelength) then range dramatically increases since the body is not absorbing the radiation.

The problem with UHF is that it is not a magnetically coupled system. It uses EM field pulse transmissions which sort of “bounce” off the tag… the method is actually called backscatter. Because UHF tags only get a super tiny fraction of the energy the reader panel puts out, and the fact the EM emissions are readily absorbed by water and reflected by metals, interference is a serious problem for UHF. Unlike coupled systems though, if proper conditions are in place, extremely long range is possible. Certain lab conditions set up by RFID hackers achieved over 100 feet!!

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Yeah my reader picks up my tags by bouncing off my roof when I’m working on it :sweat_smile: can be annoying

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