Skeletal remains of a CharlieCard

Funktionslust reports that if you put a CharlieCard in acetone for about 20 minutes, all of the plastic dissolves and what you're left with is some strands of copper (which act as an antenna) and the RFID chip that does all the magic. Photo.

Tomorrow, she plans to try it out to see if it still works.

UPDATE: It does.



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    Charlie clothing or charlie bags?

    Maybe custom covers with custom graphics?

    Nice work

    Interesting! I thought there was something in the middle of the card, which was why I had read early on that you shouldn't punch a hole in it (to attach a lanyard). Or maybe it was because you shouldn't make a hole too close to a corner.

    Not the middle of the card, exactly

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    I don't know if it's because my card is getting worn down from being squashed in my wallet or something, but if you hold it up to the light just right, you can see a small squarish thing in the lower right, to the right of "Authority" and under the guy with the beard. That's the chip.

    Hole Punch

    The copper loop is the "antenna" for the chip - would looping a metal ring through the area where there is no chip or wire interfere with the RF operation?

    I think the suggestion not to

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    I think the suggestion not to punch holes in it is just that it's not obvious where it is and isn't safe, and a blanket "don't do that" is a lot simpler. There is also some potential for messing with the RF if you loop metal through it, but that's a smaller concern.

    Punching a hole will damage

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    Punching a hole will damage the plastic and can crack it to the point where the antenna will break.

    I wonder if the quality control of how the RFID chip and antenna

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    is placed within the card is good enough for each and every card produced that you could reliably identify a useful location to punch a hole. If antenna placement is reliably consistent, then the T could probably specify that the cards already have a punch hole in them when they are made in the first place.