A theoretical model for multi-layer jamming systems

On-demand stiffening methods are receiving increasing attention from the soft robotics community, due to the need of both flexibility and stiffness in many applications. Among the various methods, jamming-based techniques became very popular thanks to features such as fast and reversible transition between flexible and rigid states and easy fabrication. However, an analytical model of these structure, taking into account the nonlinearities involved in the change in stiffness, is a challenging task. In this effort, we propose an analytical model for predicting the change in the bending stiffness of a multi-layer jamming structure. We then compare our model with finite elements simulations, showing a very good agreement. The proposed model captures the intrinsic mechanics of these systems and provides a powerful tool for properly design their response to meet the requirement needed for a specific application.