An Analytical Model for Cantilever Layer-Jamming Structures

Recently, tunable stiffness methods have been actively researched, since many applications in soft robotics require both conformability and stiffness. Jamming-based techniques provide a promising solution since they are easy to fabricate, easily scalable, and capable of rapidly tuning their stiffness. Layer-jamming structures are usually fabricated using thin sheets placed in an airtight membrane. When a pressure gradient is applied, frictional coupling prevents layers from sliding, causing a dramatic increase in stiffness. Despite the increasing interest, few works have provided analytical models to describe their behavior. In this paper, we extend our recent analytical model to the case of a cantilever layer-jamming structure. Finite elements simulations were performed to corroborate our hypothesis, showing a very good match for small deflections. We believe that the understanding of slip propagation in these systems was an essential missing step that will lead to the design of more advanced tunable stiffness robots.