An origami-inspired 3D-printed soft foldable actuator with large contraction deformation and strong actuation capability

Abstract Soft actuators are increasingly drawing attention in robotic application with human–robot interaction. To tackle the challenging actuation problem confronted in the field of soft robotics or bionic engineering, combining origami technique with 3D printing manufacturing method, we propose an origami-inspired 3D-printed soft foldable actuator with the Kresling pattern that can be made in one go. The SFA is composed of a four-layer origami chamber made from soft materials with high resilience and high strength, which is capable of lifting a maximum weight of 2000 g with a contraction ratio of 62%, enduring a vacuum pressure up to 99.8 kPa while tuning longitudinal contraction deformation. Besides, it can generate a high stroke and a large driving force throughout the whole deformation process. Based on the principle of work equilibrium and combined with geometric theory, an analytical theoretical model that can evaluate large contraction deformation and actuation performance is established and validated experimentally, which is helpful for designing other similar soft actuators. Moreover, we analyze the effect of different structural parameters on actuation characteristics of the actuator and obtain an optimized SFA with best matched structural parameters. The SFA possessing multifunctional features is conducive to flexion and extension movement of a bionic anthropomorphic leg and can complete effective actions in some application scenarios including kicking ball, running exercise and grasping target objects, which opens up new opportunities for human–robot interaction and collaboration.