[Benjamin Blundell] loves wearable technology — but isn’t very happy with commercial offerings — at least not yet. He wanted to take one of his personal RFID cards, and fit it into a much smaller form factor, a 3D printed RFID ring.
The cool thing with most RFID cards today is they are made of a plastic that is quite easily dis-solvable in Acetone. Simply soak the card for about 30 minutes (depends on the card) and the plastic will simply peel away, revealing the microchip and copper antenna coil. It kind of looks alive when it’s melting…
The problem is, the antenna coil is generally the size of the card — how exactly are you going to fit that into a ring? [Benjamin] managed to find some surrogate RFID key tags, with a much smaller antenna coil. A little bit of solder later and he was able to attach his RFID microchip onto the new antenna! He mentions it is possible to wind your own antenna… but to get the frequency just right might be a bit challenging.
With his working RFID circuit complete, he quickly designed a ring in Blender and sent it off to Shapeways to be printed. It all fit together, and works perfectly!