Designing Soft Arms with Octopus-Like Dexterity: Insights from Magnetic Resonance Imaging and Finite Element Analysis

Area of Science:

• Robotics
• Biomimetics
• Comparative Anatomy

Background:

• Octopuses exhibit complex movements without skeletons, serving as models for soft robotics.
• Previous research focused on octopus arm motion, but muscle distribution and function remain unclear.

Purpose of the Study:

• To investigate the spatial distribution of octopus arm muscles and their functional implications.
• To inform the design of bioinspired soft robotic arms based on octopus anatomy.

Main Methods:

• High-resolution magnetic resonance imaging (MRI) of Octopus bimaculoides arms.
• Finite element analysis (FEA) of four soft robotic arm models with varying muscle distributions and axial cores.
• Parametric analysis of muscle activation effects on arm curvature.

Main Results:

• MRI revealed a decrease in transverse muscle area and increase in axial core area from proximal to distal arm regions.
• The bioinspired soft robotic arm model without an axial core demonstrated superior tip displacement.
• Modulating transverse and longitudinal muscle activation significantly altered arm curvature in FEA models.

Conclusions:

• Octopus arm anatomy provides valuable insights for designing agile soft robotic arms.
• Bioinspired architectures can achieve complex movements through simple muscle activation modulation.
• Minimizing the axial core may enhance robotic arm performance, contrary to initial hypotheses.