Octopus-inspired multi-arm robotic swimming.

Area of Science:

• Robotics
• Biomimetics
• Fluid Dynamics

Background:

• Octopus locomotion, particularly arm-swimming, offers unique capabilities for underwater movement.
• Existing robotic systems often rely on jetting, limiting maneuverability and efficiency.

Purpose of the Study:

• To develop and investigate a multi-functional robotic swimmer inspired by octopus arm-swimming.
• To explore the propulsive capabilities and maneuverability of such a system using various arm coordination gaits.

Main Methods:

• Developed a lumped-element model to simulate robotic swimmer dynamics, including arm compliance and environmental interaction.
• Designed and tested a compliant-body robotic prototype with eight polyurethane arms in a water tank.
• Investigated various swimming gaits for forward, backward, and turning propulsion.

Main Results:

• Achieved speeds up to 0.26 body lengths per second and propulsive forces up to 3.5 N.
• Demonstrated efficient propulsion with a non-dimensional cost of transport as low as 0.9 with two active arms.
• Verified multi-arm maneuverability and simultaneous object grasping capabilities.

Conclusions:

• Octopus-inspired arm-swimming provides a novel and effective mode of underwater propulsion for robotic systems.
• The developed robotic swimmer shows significant potential for underwater applications requiring both locomotion and manipulation.
• Bio-inspired designs offer promising avenues for advancing robotic capabilities in complex environments.