Let's talk about fingerprint systems. They suck.
A fingerprint is a non-replaceable object and it can be easily compromised. Moreover, there is a limited stock of them.
Therefore, at the end, all these give me a correct finger and I will let you in systems are neither secure enough nor reliable. They need to be improved and here is the idea - a Masonic touch.
Instead of asking any valid finger, a system must ask a correct sequence of valid fingers.
For example, the system must require a valid thumb finger, then an index finger, then again an index finger and a little finger.
This way we enhance authentication factor from something we have to something we have plus something we know. In other words, biometrics itself becomes a two factors authentication, rather than just being a second or a single factor. As simple as is.