3D-Printed Shape-Memory Polymer-Based Variable-Stiffness Origami Actuator for Multimodal Soft Continuum Robots.

Soft continuum robots have garnered much attention due to their inherent compliance and interaction ability in complex scenarios. However, the absence of rigid supports in them often causes deformation or instability under large external loads, significantly limiting their applications. Here, we propose a solution that integrates origami-inspired modules with variable-stiffness hinges into soft continuum robots via 3D printing to enable both high load-bearing capacity and versatile deformation. Our innovative design leverages the unique properties of shape-memory polymers to facilitate a seamless transition between soft and stiff states, thereby allowing for dynamic deformations of the robots upon actuation, followed by structural locking to enhance their load-bearing capacity and stability. By integrating multiple Kresling origami modules with selective heating and actuation, our design enables precise and programmable multimodal deformation. This modular approach allows for customizable motion patterns, significantly enhancing the system's scalability and adaptability to diverse applications. To validate the versatility and stability of the proposed multisegment continuum robots, we conducted a series of experiments, demonstrating selective bending in a two-segment configuration, as well as complex tasks such as bottle opening and load-bearing in a three-segment configuration.