Tension Jamming for Deployable Structures

Deployable structures provide adaptability and versatility for applications such as temporary architectures, space structures, and biomedical devices. Jamming is a mechanical phenomenon with which dramatic changes in stiffness can be achieved by increasing the frictional and kinematic coupling between constituents in a structure by applying an external pressure. This study applies jamming, which has been primarily used in medium-scale soft robotics applications to large-scale deployable structures with components that are soft and compact during transport, but rigid upon deployment. It proposes a new jamming structure with a novel built-in actuation mechanism which enables high-performance at large scales: a composite beam made of rectangular segments along a cable which can be pre-tensioned and thus jammed. Two theoretical models are developed to provide insights into the mechanical behavior of the composite beams and predict their performance under loading. A scale model of a deployable bridge is built using the tension-based composite beams, and the bridge is deployed and assembled by air with a drone demonstrating the versatility and viability of the proposed approach for robotics applications.