A Novel Implementation of a Flexible Robotic Fin Actuated by Shape Memory Alloy

In this paper, study of a novel flexible robotic-fin actuated by Shape Memory Alloy (SMA) is presented. The developed robotic fin is capable of implementing various 3-Dimensional (3D) motions, which plays an important role in robot propulsion and maneuverability. Firstly, the morphological and mechanics parameters of a real pectoral fin from a carp are investigated. Secondly, a detailed design of the flexible pectoral fin driven by SMA is presented according to the previous morphological and mechanics analyses. Thirdly, a simplified theoretical model on the SMA fin plate is derived. The thermodynamics of the SMA plate and the relationship between curvature and phase transformation are analyzed. Finally, several simulations and model experiments are conducted according to the previous analyses. The results of the experiments are useful for the control of the robotic fin. The experimental results reveal that the SMA actuated fin ray has a good actuating performance.