Fin ray-inspired, Origami, Small Scale Actuator for Fin Manipulation in Aquatic Bioinspired Robots

TL;DR

This paper presents a low-cost, origami-inspired fin ray actuator that emulates fish fin dynamics, enabling efficient aquatic propulsion and control in bioinspired robots, validated through extensive kinematic and swimming studies.

Contribution

Introduces a novel, inexpensive origami electromagnetic tendon-driven actuator that replicates fish fin ray mechanics for use in aquatic bioinspired robots.

Findings

Successfully embedded eight actuators in a 135 mm cuttlefish robot for four degrees of freedom.

Extensive data collection validated the actuator's kinematic performance and swimming efficiency.

Demonstrated versatility by integrating the actuator into fish and jellyfish robots.

Abstract

Fish locomotion is enabled by fin rays-actively deformable boney rods, which manipulate the fin to facilitate complex interaction with surrounding water and enable propulsion. Replicating the performance and kinematics of the biological fin ray from an engineering perspective is a challenging task and has not been realised thus far. This work introduces a prototype of a fin ray-inspired origami electromagnetic tendon-driven (FOLD) actuator, designed to emulate the functional dynamics of fish fin rays. Constructed in minutes using origami/kirigami and paper joinery techniques from flat laser-cut polypropylene film, this actuator is low-cost at {\pounds}0.80 (\$1), simple to assemble, and durable for over one million cycles. We leverage its small size to embed eight into two fin membranes of a 135 mm long cuttlefish robot capable of four degrees of freedom swimming. We present an extensive kinematic and swimming parametric study with 1015 data points from 7.6 hours of video, which has been used to determine optimal kinematic parameters and validate theoretical constants observed in aquatic animals. Notably, the study explores the nuanced interplay between undulation patterns, power distribution, and locomotion efficiency, underscoring the potential of the actuator as a model system for the investigation of energy-efficient propulsion and control of bioinspired systems. The versatility of the actuator is further demonstrated by its integration into a fish and a jellyfish.