Metamaterial-Reinforced Origami Soft Actuators: Reconfigurable Stiffness and Deformation

Soft origami-inspired pneumatic actuators have emerged as promising systems in soft robotics due to their high contraction and force-to-pressure ratios. Despite various strategies proposed for programming stiffness of origami structures, challenges remain in managing control complexity while maintaining high deformation ranges. Metamaterials are at the forefront of mechanical engineering, offering unique and programmable mechanical properties of the designed structures. In this work, we propose monolithic origami-inspired actuators reinforced with cellular metamaterials. These structures were evaluated as independent origami structures to characterize their stiffness through finite element models and experimental tests, demonstrating agreement between the methods. Multilevel origami towers were designed with various combinations of metamaterial reinforcements, and their deformation performance was assessed. Finally, a parallel platform and a robotic arm were constructed as case studies to showcase the application of these actuators. This study highlights the potential of leveraging metamaterial reinforcements to develop programmable soft actuators for robotic applications.