A 3D printed hydrostatic skeleton for an earthworm-inspired soft burrowing robot

Area of Science:

• Robotics
• Biomimetics
• Materials Science

Background:

• Soil locomotion presents significant challenges for robotic systems, especially soft robots.
• Existing robotic designs often struggle with the complex and deformable nature of soil.

Purpose of the Study:

• To develop a soft robotic system inspired by the earthworm's hydrostatic skeleton for effective soil traversal.
• To engineer worm-sized, highly deformable segments for enhanced mobility in subterranean environments.

Main Methods:

• Utilized a specialized 3D printer for low-hardness rubber to create thin-walled, flexible segments.
• Investigated soft material properties and segment geometry to achieve large radial deformation.
• Integrated multiply-wound shape memory alloy wires for segment actuation.
• Constructed a series-connected, earthworm robot composed of these actuated segments.

Main Results:

• Successfully demonstrated soil propulsion with the constructed earthworm robot.
• The robot achieved a small diameter of 10 mm, enabling navigation in confined spaces.
• The robot exhibited efficient peristaltic motion, mimicking earthworm locomotion.

Conclusions:

• The proposed earthworm-inspired robot offers a unique solution for soft robotic locomotion in soil.
• The hydrostatic skeleton-based design and shape memory alloy actuation enable effective subterranean movement.
• This research opens avenues for developing miniature, agile robots for soil exploration and interaction.