Jellyfish-Inspired Soft Robot Driven by Pneumatic Bistable Actuators.

Area of Science:

• Robotics
• Biomimetics
• Fluid Dynamics

Background:

• Soft actuators face challenges in achieving high driving force and fast response speeds for practical applications.
• Jellyfish exhibit efficient water-jet propulsion through subumbrellar muscle motion, offering a model for biomimetic designs.

Purpose of the Study:

• To design, fabricate, and analyze a soft pneumatic bistable actuator (PBA) mimicking jellyfish muscle motion for water-jet propulsion.
• To integrate the PBA into a jellyfish-like prototype and evaluate its swimming performance and load-bearing capacity.

Main Methods:

• Developed an elastic band stretch prebending PBA with a simple structure and low inflation cost.
• Integrated the PBA into a jellyfish-like prototype, incorporating a skin-like structure to optimize fluid dynamics.
• Analyzed the swimming performance, including speed and load capacity, of the tethered and untethered prototypes.

Main Results:

• The PBA demonstrated exceptional driving performance and stable force output.
• The jellyfish-like prototype achieved swimming speeds of 3.8 cm/s (tethered) and 4.7 cm/s (untethered).
• The prototype exhibited notable load-bearing capacity and fast-forward swimming compared to other underwater biomimetic robots.

Conclusions:

• The developed soft pneumatic bistable actuator effectively mimics jellyfish propulsion for efficient water-jetting.
• The integration of skin-like structures enhances the maneuverability and efficiency of soft robotic systems.
• This research offers insights for creating agile, fast-responsive soft robots for underwater applications.