The motion will be on the four fingers of the hand, which will move consecutively with a bit of overlap. I know that I want the motion to be revolving around one axel, allowing the use of just one servo motor.
Idea #1:
Four rods that go through the fingers will be rotating around one axel. Fixed to another axel will be circular shapes with a protruding bump that are positioned to hit the rods at certain times.
Idea #2:
The four fingers will have one rod going through the knuckles. The motor and mechanism will be placed below the hand and used to push up rods that will nudge the fingers up. The mechanism will be made up of one axle, on which circles will be rotating. The circular pieces will be rotating off centre in order to bump the rods at different heights.