A Stiffness-Tunable Soft Actuator with Adjustable Jamming for Dexterous Manipulation

Area of Science:

• Robotics
• Materials Science
• Mechanical Engineering

Background:

• Soft robotic actuators require adaptable stiffness and controllable bending for advanced manipulation.
• Existing soft fingers often lack the ability to dynamically adjust their physical properties.
• Hybrid jamming techniques offer potential for enhanced actuator performance.

Purpose of the Study:

• To introduce a novel soft robotic finger, the Jamming Adjustable PneuNet Actuator (JAPA).
• To demonstrate JAPA's capability for simultaneous stiffness modulation and tunable bending.
• To evaluate JAPA's performance in force control, dexterity, and object manipulation.

Main Methods:

• Developed JAPA using a flexible hybrid jamming approach, combining layer and granular jamming.
• Integrated a magnetically positioned sliding mechanism to adjust layer jamming length for dynamic bending profile reshaping.
• Incorporated distributed granular jamming for adaptive stiffness reinforcement.

Main Results:

• JAPA achieved a maximum stiffness gain of 3.55×.
• Demonstrated over 200% workspace expansion and >300% improvement in multidirectional force modulation.
• Successfully operated a computer cursor and manipulated diverse objects with a JAPA gripper.

Conclusions:

• JAPA offers significant advancements in multidirectional force control and dexterity.
• The design enables safe handling of delicate and irregularly shaped objects.
• JAPA shows promise for assistive robotics, adaptive grasping, and human-interactive devices.