Contact-Rich Soft-Rigid Robots Inspired by Push Puppets

Abstract

Human-centric problem domains will require robots with an unprecedented mix of traits-combining the inherent safety and robustness of soft materials with the strength and precision of rigid systems. Foundational work is needed to understand how to design and simulate a new generation of hybrid, soft-rigid robots. We draw inspiration from the classic push puppet toy to design soft-rigid robot modules capable of transitioning between soft and rigid states. We show how multiple modules can be combined into exciting exemplar robots, such as a shape-shifting soft-rigid arm. We also show how to build differentiable finite element-based simulations of these robots, including state-of-the-art soft body contact and motorized revolute joints.