Amplified Actuation in Symmetric Origami Mechanisms

The integration of soft actuating materials within origami-based mechanisms is a novel method to amplify the actuated motion and tune the compliance of the system for low stiffness applications. Origami structures provide natural flexibility given the extreme geometric difference between thickness and length, and the energetically preferred bending deformation mode can naturally be used as a form of actuation. However, origami fold patterns with specific actuation motions and mechanical loading scenarios are needed to expand the library of fold-based actuation strategies. In this study, an optimization framework is utilized to predict actuator topologies with different symmetry groups of input and output conditions with respect to the boundary conditions. Utilizing the patterns discovered through the optimization, the multistability of the actuator is further characterized through computational tracking of the bifurcating equilibrium branches and through empirical demonstration with actuator prototypes. This survey of origami mechanisms, comparison of actuation efficiency, and characterization of multistability provides a new set of origami actuators for future integration with soft actuating materials.