Design and analysis of a biomimetic wire-driven flapping propeller

Caudal fin is the most important organ for fish movement. It adopts flapping as the way to generate thrust. This inspires the building of robot fish. However, current robotic fins are mostly rigid and far unlike their nature counterpart. In this paper, a novel wire-driven flapping propeller is designed. It is made of a continuous backbone and a fin. The fin is attached to the backbone, which is actuated by the wire-driven mechanism, and flaps along with the reciprocating bending of the backbone. The propulsion model is built based on Lighthill's propulsion model. The propeller's performance is evaluated by simulation. From the results, the reason for fish adopting C-shape fast start scheme is also explained.