An earthworm-like modular soft robot for locomotion in multi-terrain environments

Area of Science:

• Robotics
• Bio-inspired Engineering
• Soft Matter Physics

Background:

• Subterranean robotic locomotion faces challenges due to high pressure, friction, and unstructured environments.
• Existing robotic designs struggle with burrowing and movement in confined, high-resistance conditions.
• Earthworm locomotion, utilizing antagonistic muscle contractions and coelomic chambers, offers a biomimetic model for soft robotics.

Purpose of the Study:

• To design and develop a modular soft robot capable of peristaltic locomotion inspired by earthworm mechanics.
• To investigate the functionality of a peristaltic soft actuator (PSA) for generating axial and radial forces.
• To analyze the influence of fluid properties and external friction on robotic locomotion in various media.

Main Methods:

• Development of a modular soft robot utilizing a novel peristaltic soft actuator (PSA) based on earthworm anatomy.
• PSA design featuring a bellows-like structure capable of bidirectional deformation via positive and negative pressure.
• Experimental locomotion tests in different media, including investigation of friction reduction using passive scales mimicking earthworm setae.

Main Results:

• The PSA demonstrated versatile control, generating longitudinal force for penetration and radial force for anchorage.
• Robot performance, including force and displacement, was tunable by altering the fluid within the elastomer chamber.
• The five-module robot successfully achieved peristaltic locomotion in various environments, with friction modulation enhancing movement.
• Passive scales significantly influenced locomotion, highlighting the role of friction in subterranean movement.

Conclusions:

• A novel peristaltic earthworm-like soft robot was successfully developed, offering a new approach to subterranean locomotion.
• The study provides a deeper understanding of bio-inspired locomotion mechanisms and their application in soft robotics.
• The modular PSA design offers a versatile and controllable platform for navigating challenging, unstructured environments.