A Soft‐Robotic Harbor Porpoise Pectoral Fin Driven by Coiled Polymer Actuators as Artificial Muscles

Abstract

Biomimicry is an approach in science and engineering to overcome human challenges by designing materials and systems modeled after nature. Selected applications of biomimicry include catheters, hearing devices, and artificial appendages such as arms, legs, and fingers. The inspiration for this study is the hydrofoil‐like structured pectoral fin of the harbor porpoise whale that is ultimately useful for studying fluid‐structure interactions, drag, lift, and laminar‐to‐turbulent transitions. The pectoral fin is fabricated by manipulating computed tomography (CT) scans into 3D models using Simpleware ScanIP and post‐processed in Autodesk for printing. An array of thermally driven coiled polymer actuators (CPA) fabricated from nylon and heated with Nichrome are used as artificial muscles for the fabricated pectoral fin. The CPAs are of great interest due to its high specific power and large actuation stroke. The work discussed includes the fabrication of the fin (designing, printing, and assembly), the fabrication and testing of the CPAs, implementation of the CPAs, controlling, and actuation of the bio‐inspired whale fin.