Dhani Sutanto has created unique rings embedded with the RFID chip from the London Oyster Card. The transport card is dissolved in a solution of nail polish remover, where the laminate breaks down so you can retrieve the chip and antenna still intact.
Sutanto is able to then turn the extracted chip and antenna into a ring by embedding them in resin. The designer filmed herself using the Oyster ring to access the London train system, but wrote a disclaimer advising users that:
Bear in mind that it’s illegal to create something like this and it was quite a nerve wrecking adventure to use the ring, let alone film it.
But for the sake of art and technology, a little bit of experiment with breaking the law must be done.