Enhanced Interlocking in Granular Jamming Grippers through Hard and Soft Particle Mixtures

TL;DR

This study explores how mixing soft and rigid particles in granular jamming grippers enhances their grasping ability by improving object wrapping and increasing holding force, offering a tunable design strategy.

Contribution

It demonstrates that combining soft and rigid particles optimizes grasping performance, a novel approach in granular gripper design.

Findings

Soft particles improve object wrapping after jamming.

Adding rigid particles increases maximum holding force.

Mixture tuning enhances gripper performance.

Abstract

We investigate the influence of particle stiffness on the grasping performance of granular grippers, a class of soft robotic effectors that utilize granular jamming for object manipulation. Through experimental analyses and X-ray imaging, we show that grippers with soft particles exhibit improved wrapping of the object after jamming, in contrast to grippers with rigid particles. This results in significantly increased holding force through the interlocking. The addition of a small proportion of rigid particles into a predominantly soft particle mixture maintains the improved wrapping but also significantly increases the maximum holding force. These results suggest a tunable approach to optimizing the design of granular grippers for improved performance in soft robotics applications.