A Passively Conforming Soft Robotic Gripper with Three-Dimensional Negative Bending Stiffness Fingers

Area of Science:

• Robotics
• Materials Science
• Mechanical Engineering

Background:

• Traditional robot grippers struggle with object uncertainty and require large workspaces.
• Existing soft robotic grippers have limitations in cluttered environments due to actuated finger designs.

Purpose of the Study:

• To develop a novel soft robotic gripper with passively conforming fingers.
• To enable robust grasping of delicate and irregularly shaped objects in cluttered spaces.

Main Methods:

• Designed and fabricated three-dimensional conical structures exhibiting negative stiffness for gripper fingers.
• Utilized analytical and experimental methods to validate the negative bending response and conforming capabilities.
• Demonstrated a soft robotic gripper with three self-conforming fingers performing various grasping tasks.

Main Results:

• The proposed fingers exhibit negative bending, enabling passive conformation to objects of varying diameters.
• A 100% grasp success rate was achieved when picking fruits, demonstrating adaptability to complex geometries.
• The gripper successfully performed fingertip, power, and semipassive grasping in cluttered environments without complex algorithms.

Conclusions:

• The developed passively conforming fingers offer a robust solution for adaptive grasping in unstructured environments.
• This approach overcomes limitations of traditional and existing soft grippers, enabling manipulation of delicate objects.
• The tunable nature of the structures allows for tailored compliance, advancing soft robotics design.