RFID Bracelet: Remote control doors

Picture of RFID Bracelet: Remote control doors
Getting through RFID key-card doors is a pain in the behind when your hands are full of books or files, and your key-card is in your pocket, or swinging free on a lanyard.

To address this problem, GeeDee86 let me have some redundant cards to play with, and I managed to turn the cards into bracelets.

Caveat: This technique should work on most cards with RFIDs embedded, but be aware that it is not acceptable to do it to some payment cards, such as the Oyster card you use to pay for your London commute. Check the ToS of your particular card, and look for clauses on mutilation.

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Step 1: Materials and tools

Picture of Materials and tools
As well as the card*, you need:
  • Non-polar solvent, such as nail varnish remover, paint thinners, acetone or petrol.
  • Shallow  non-plastic tray or dish. 
  • Tools to prod and stir.  Wooden coffee stirrers, metal forceps or narrow-nosed pliers are ideal.
  • Non-metallic material to make a bracelet. I used a popsicle stick, but you could use papier mache, thin plywood, heavy fabric, scrap acrylic etc.
  • Superglue.
  • Tools appropriate to your materials
  • Glues or paints as required to finish the bracelet materials, if desired.

Safety: Most non-polar solvents can cause contact dermatitis, so I recommend using protective gloves and eye protection. You also need to ensure that you have plenty of ventilation, as the fumes are toxic and do odd things to your head, and the fumes of most solvents are highly flammable, so be aware of your personal fire precautions.

*I have no images of the cards before starting the project, in order to comply with Data Protection legislation.
Kiteman (author) 8 months ago
I would appreciate your vote - please click the red "ribbon" at the top-right of the page.
rimar20008 months ago
Very clever, Kiteman.
ninja_maker8 months ago
Could you put something over the bracelet, like leather or my favorite substance, sugru? and could you perhaps do this to a watch or other types of wristbands? or would the watch be too thick for it to be read?
Kiteman (author)  ninja_maker8 months ago
You could cover it, just not to thickly. Putting it on a watch strap is a good idea, some folk might find it more comfortable.
BMR111009 months ago
How did of that ure a genius I love the idea
Kiteman (author)  BMR111009 months ago
It's not a new idea, just a different take on it.
tovey9 months ago
Why not just make a leather bracelet with a card pocket. You can use thin leather to make the card pocket and insert the card into.

The thing with this is that you may want the card to sit vertically on the fore arm so the bracelet would need to be as wide as the card is long. A couple benefits to this is that a watch can be attached and it would appear to be just a watch with an unusually wide band. A bill or two stuffed beneath the card makes for a simple emergency money spot.
Kiteman (author)  tovey9 months ago
That would work, but be far larger than this version. You'd effectively be strapping your wallet to your wrist, which doesn't really work in a "suit" environment, and clashes with a lot of folk's style choices.
bronston9 months ago
Great idea. Just a thought. I believe the issue with the chip needing read not the antenna is the antenna is actually an inductor gathering power to power the chip not necessarily transmitting data. Forgive me if I'm mistaken, I haven't played with that tech in a while.
Kiteman (author)  bronston9 months ago
I think you're right - the location of the chip was just coincidental to the ideal angle oc the antenna.
imperio9 months ago
very good idea!
Kiteman (author)  imperio9 months ago
Thank you.
Jaie9 months ago
Could you cast this in resin, and make this more decorative?
Kiteman (author)  Jaie9 months ago
I expect you could, yes.
superthrust9 months ago
Really interesting. I wanna see if and how this works and if I could apply this to a paracord bracelet I have, like weaving it around it. I use rfid cards st work and it's hell trying to carry stuff around and always having to use it... Very very secure building.
Just to clarify: this is an NFC bracelet, at least based on how you actually have to hold it close to the reader to open the door. Real RFID has a longer range. The distinction is important because RFID can be tracked remotely without the wearer knowing, while NFC can't.
Kiteman (author)  .NetRolller 3D9 months ago
Thanks for the clatification.
irawans9 months ago
It remains me to pledge here:
ironorr849 months ago
I suppose this is a good idea. However, when that time comes when it's required to have these RFID chips implanted in your body, I will absolutely refuse these devices for all reasons and accounts...

Call me paranoid, but you'll day we'll be required by law to get them under our skins to be tracked...
monty3249 months ago
This reminds me of something i saw online the other day. Apparently some hobbyists had glass RFID capsules implanted into their hand for this purpose.
Kiteman (author)  monty3249 months ago
I remember Kevin Warwick's implant being on the news.
billbillt9 months ago
great idea
Kiteman (author)  billbillt9 months ago
Thank you!
Honus9 months ago
You could also probably coat the outside of the bracelet with epoxy resin to make it more durable.
Kiteman (author)  Honus9 months ago
That would be a good idea, if I had some resin...
Honus9 months ago
Very cool. I have a few RFID cards I'll have to try this with.

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