When I was a more active member of a makerspace, I had this idea to help cosplayers who had a complicated costume and looking for a way to control it: make jewelry that was a touch-sensor and could used to puppet a costume surreptitiously.

The prototype works, but I’m still working on a version that looks good enough to be part of a costume.

Between the ring and your ring finger is a Teflon liner, and the ring is coated in epoxy, which preserves the polish and keeps the electric charge from shocking you or damaging your phone, etc. It works by connecting the rings and the bracelet with a thin magnet wire to hold the beads. This carries an electric voltage that is constantly oscillating between 0V and 5V.

The system measures how quickly the voltage changes to 5V and that measures the capacitance of the ring; if it can hold more charge before the voltage rises to 5V; it has a larger capacitance. When does it have a larger capacitance? When your electrically-conductive and electrically-grounded other fingers touch it. The epoxy is both thinner and has a higher electric permittivity than the teflon liner, so it makes a better capacitor then between the ring and your ring finger. The system detects the change and calls it “touched”.

Obviously, I didn’t invent the whole idea; that’s probably Apple, if memory serves. But I think it’s coming along well and could be useful to someone.

The next step will be to connect it to generative music AI so your DM can touch a ring to “make the music spookier” or “play the canon sound”. Or maybe something useful. Who knows?