Analysis and Testing of Shape Memory Alloy Driven Biorobotic Fish Fins with Multi Propulsion Modes

摘要

Biomimetic design takes principles from nature to employ in engineering problems.However,the emulation of specific biological devices poses a great challenge because of complicated,arbitrary,and over-redundant designs.Smart material driven mechanisms are of immediate appeal in addressing the problem of complex,biomimetic deformation because of their inherent flexibility.Here,Shape Memory Alloys(SMAs)are selected to develop a biologically-inspired robotic fish fin.Shape Memory Alloys are metals,which have the ability to change shape,stiffness,position,natural frequency and other mechanical characteristics in response to temperature.This robotic fin consists of several SMA actuators(“fin rays”)arranged in a series and interconnected via a flexible material(“fin membrane”).Initial testing has concentrated on two dimensional fin ray motions,whereby each SMA fin ray moves laterally.We achieved active deformation control of our developed biorobotic fish fins,realized multi propulsion modes of this fin such as oscillating and undulating motion.The influence of thickness of SMA fin ray on deformation performance is also tested.