Bi-Shell Valve for Fast Actuation of Soft Pneumatic Actuators via Shell Snapping Interaction

Area of Science:

• Robotics
• Materials Science
• Fluid Dynamics

Background:

• Achieving rapid motion in soft pneumatic robots typically requires complex methods like fast volume input, integrated power sources, or embedded elastic instabilities.
• Existing valves primarily focus on fluidic flow regulation, not rapid actuation.

Purpose of the Study:

• To present a novel bi-shell valve capable of fast actuation for soft pneumatic robots.
• To demonstrate a mechanism that converts slow volume input into fast volume output without altering actuator architecture or relying on advanced pressure control.

Main Methods:

• The study designed and analyzed a bi-shell valve composed of a spherical cap and an imperfect shell with a defect.
• Shell snapping interaction was utilized to achieve the desired volume conversion.
• Experimental validation was performed to analyze the valve's performance and demonstrate its functionality.

Main Results:

• The bi-shell valve successfully converts slow volume input into fast volume output, enabling rapid actuation.
• The spherical cap determines snapping pressure thresholds and output bounds, while the imperfect shell facilitates energy storage and release.
• Experimental results validated the valve's performance, and geometry variations showed its versatility.

Conclusions:

• The developed bi-shell valve offers a new method for fast actuation in soft pneumatic robots.
• This technology provides a versatile and effective solution for rapid fluidic control, as demonstrated by actuating a striker.