Chain-Like Granular Jamming: A Novel Stiffness-Programmable Mechanism for Soft Robotics

Area of Science:

• Robotics
• Materials Science
• Mechanical Engineering

Background:

• Soft robots require adaptable stiffness for effective environmental interaction.
• Existing granular jamming systems often rely on vacuum, limiting their application.

Purpose of the Study:

• To introduce a novel chain-like granular jamming mechanism (CLS) for large-range stiffness variation.
• To develop and validate a soft-rigid hybrid actuator and an anthropomorphic hand using the CLS.

Main Methods:

• Theoretical modeling to optimize granule combination for CLS.
• Experimental validation of the CLS stiffness variation.
• Fabrication and testing of a soft-rigid hybrid actuator and an anthropomorphic hand.

Main Results:

• The CLS achieved a stiffness variation range of 50.7 folds.
• The anthropomorphic hand demonstrated versatility in manipulating diverse objects in a soft state.
• The hand successfully lifted heavy objects (1.5 kg cylindrical grasp, 3.52 kg hook grasp) in a rigid state.

Conclusions:

• The novel CLS offers a significant advancement in tunable stiffness for soft robotics.
• The soft-rigid hybrid actuator and anthropomorphic hand show great potential for practical robotic applications.
• Integration into a service robot improved practicability and safety in human interaction.