A Soft Robot Driven by a Spring-Rolling Dielectric Elastomer Actuator with Two Bristles.

Area of Science:

• Robotics
• Materials Science
• Mechanical Engineering

Background:

• Confined space inspections, such as pipeline assessments, require robots capable of navigating complex and unstructured environments.
• Lightweight soft robots offer inherent compliance, making them suitable for adapting to varying internal dimensions and geometries.

Purpose of the Study:

• To propose and investigate a tubular soft robot utilizing a spring-rolled dielectric elastomer (SRDE) and compliant passive bristles.
• To evaluate the robot's locomotion performance in pipelines with inner diameters both smaller and larger than its bristle diameter.
• To assess the robot's adaptability to different pipeline geometries, including curves.

Main Methods:

• Experimental investigation of the nonlinear dynamic behaviors of the SRDE.
• Fabrication of a tubular soft robot with compliant passive bristles.
• Performance testing of the robot in pipelines with inner diameters of 16 mm, 18 mm, and 20 mm.
• Evaluation of locomotion in curved pipes and on flat ground.

Main Results:

• The robot achieved locomotion through anisotropic friction in pipelines with inner diameters smaller than its bristle diameter (e.g., 1.88 body lengths/sec horizontally in 18 mm pipe).
• In larger diameter pipes, compliant bristles facilitated locomotion, resulting in higher velocities (e.g., 2.78 body lengths/sec in 20 mm pipe).
• The robot demonstrated effective navigation in curved pipes (approx. 2 body lengths/sec) and on ground (3.52 body lengths/sec).

Conclusions:

• The proposed tubular soft robot, with its SRDE and compliant bristles, exhibits versatile locomotion capabilities in diverse pipeline environments.
• The robot's design allows for effective operation in pipelines with varying diameters and geometries, demonstrating its potential for inspection tasks.
• This compliant robotic system shows significant promise for applications in pipeline inspection and narrow space exploration.