Achieving Both Conformability and Load Distribution with Granular Jamming Beams

Abstract

Typically, soft structures are needed to conform to curved or irregular surfaces, but they are not very good at transferring adhesive loads from a single attachment point to their entire area on account of their low stiffness. Conversely, stiff structures achieve excellent load distribution over large areas, but cannot be used on surfaces with a different curvature. In this paper, we present granular jamming as a new solution to the problem of conforming to curved or irregular surfaces and then stiffening to distribute adhesive forces over the entire contact area. We demonstrate this with a granular jamming beam equipped with five suction cups along its length. We show that this structure can not only conform to a flat object and two curved objects, but also can support loads of 84.7% of a rigid beam. We also propose that the Flexural Compliance is a measure of how readily a structure can conform to surfaces with different radii and support adhesive forces across its body. We simulate the maximum loads that can be supported by a beam with different values for the Flexural Compliance, and experimentally verify this for a number of different beams with different values of Flexural Compliance.