OP asked for "biometric" ID, okay? RFID, cards, NFC, etc. are not biometric. The reasonable assumption -- unlike yours -- is that he had an actual REASON for asking for biometrics. People don't usually say things for no reason.
Having said that, most consumer-level biometrics are crap. Despite Apple, fingerprint readers are crap for any kind of real security. Capacitance is even worse. You can foil it (pun intended, but pretty literally) with a tinfoil hat.
My best recommendation would be voice recognition. Not the "Hey, Google, where is 'Interstellar' playing nearby?" kind but the person-recognition kind. It's pretty good and not terribly expensive.