Here is a robot that mimics a real sea turtle’s propulsion. It has front flippers that move it forward while its hind flippers let it change direction. This robot has an oval-shaped body with 4 independently RC flippers. It also has a multisensor device and an on-board control unit. Its body frame and flipper connectors are 3D printed.
Yasemin Ozkan-Aydin, Nnamdi Chikere, and John Simon McElroy are behind this robot. You can find out more here.