This Robot Is Just My Type
YouTube channel Ancient has the coolest video I've seen all week: an automaton that lip-syncs by rotating a ball with various mouth positions, not unlike an old-fashioned IBM Selectric typewriter ball. In other words, the lips aren't making the proper shape, but the whole mouth is. It's kind of hard to explain, but you'll understand immediately once you see it. This link will take you to the demo of the effect in motion, though the whole video is really interesting if you enjoy seeing the process and . . . um . . . prototyping.
And if you'll excuse me, I have a new idea for a totally different way to design an interesting mechanoid for a 1950s GURPS Atomic Horror campaign . . .