Up and down motion

Hey guys,

I’m trying to create a robotic lizard for a expierment and Im trying to imatate a lizard bombing it’s head up an down and doing push ups. I there any easy or simple way to achieve this? Trying to be as simple as possible since I am no engineer or robotics expert. I was looking at flexinol since it looks simple. Can any of you point me in the right direction or any tips? I’m not looking for anything to program, just a simple up and down motion for now which the components will have to be fairly small since I’m trying to replicate a lizard.
Somthing like these guys did.

m.youtube.com/watch?v=hQy4qDB_5Gc

m.youtube.com/watch?feature=plcp&v=F2tcKLKVV5k

Try a 4-bar mechanism and a DC gear motor.