Ternary Origami Spring Actuator: Multimodal Deformation via Programmable Folding Sequences for Bioinspired Soft Robotics

Origami provides an efficient methodology for reconfigurable fabrication, enabling the creation of diverse origami structures through programmable folding techniques. However, conventional fold-driven structures are often limited to predefined deformation modes, while multimodal designs typically require multiple independent actuators. To address these challenges, this study proposes a ternary origami spring structure that integrates multimodal deformations into its folding sequence and achieves single pneumatic source-driven actuation. The core architecture comprises three interwoven inflatable strips, forming a programmable and reconfigurable origami actuator. Our investigation revealed that editing the folding sequence generates complex spatial trajectories. Building on this discovery, we developed a simulation algorithm to predict shape deployment based on folding sequences and utilized it for computational design. Following bio-inspired principles, functional prototypes were fabricated to validate shape-programming capabilities and operational efficacy. The independent folding scheme was also explored. This work demonstrates significant potential for autonomous design, rapid p