A Comprehensive Dataset of Grains for Granular Jamming in Soft Robotics: Grip Strength and Shock Absorption

TL;DR

This study provides a comprehensive dataset of various granular materials used in soft robotics, analyzing their grip strength and shock absorption capabilities to inform material selection.

Contribution

It introduces a detailed dataset of natural, manufactured, and 3D printed granular materials, evaluating their performance in grip and shock absorption for soft robotic applications.

Findings

Grain deformability significantly influences grip strength.

Larger grain sizes in 3D printed materials improve shock absorption.

Shape, size, and softness of grains affect their performance.

Abstract

We test grip strength and shock absorption properties of various granular material in granular jamming robotic components. The granular material comprises a range of natural, manufactured, and 3D printed material encompassing a wide range of shapes, sizes, and Shore hardness. Two main experiments are considered, both representing compelling use cases for granular jamming in soft robotics. The first experiment measures grip strength (retention force measured in Newtons) when we fill a latex balloon with the chosen grain type and use it as a granular jamming gripper to pick up a range of test objects. The second experiment measures shock absorption properties recorded by an Inertial Measurement Unit which is suspended in an envelope of granular material and dropped from a set height. Our results highlight a range of shape, size and softness effects, including that grain deformability is a key determinant of grip strength, and interestingly, that larger grain sizes in 3D printed grains create better shock absorbing materials.