Research on Biomimetic Fish Fin Driven by NiTi Shape Memory Alloy

In order to improve the maneuverability of underwater biomimetic fish-like propulsor,we recently study black ghost knifefish which typically uses undulatory locomotion of ventral ribbon fin to produce thrust.The morphology and kinematics of this ribbon fin is analyzed.Meanwhile,the fin model is simplified,and a robotic fish fin driven by shape memory alloy(SMA)is developed.Then,the mechanical structure and corresponding control circuit of this biomimetic robot fin are introduced.Particularly,the swimming velocity and thrust generated by undulatory motion of the developed robotic fin are analyzed theoretically.Furthermore,a computational fluid dynamics(CFD)method is used to show pressure distribution on robotic fin surface as well as the periodical change of generated swimming thrust with time.These computational results are compared with previous experimental value,indicating that these computational results are reasonable and correct.All these results show that it's a very interesting and feasible to study the SMA driven robotic fish fin.