Stiffness‐Programmable Origami Robots With Tendon‐Driven Actuation via Multimaterial 3D Printing

Abstract

Origami has been widely used to create various robotic systems, but it remains challenging to achieve diverse motion behaviors from a compact structure without increasing actuator complexity. This work investigates a novel method to generate distinct motion behaviors under uniform tendon actuation by leveraging programmable stiffness distributions across origami creases. Building on a modified Yoshimura pattern, our modular origami can be fabricated via low‐cost, multimaterial fused deposition modeling (FDM) 3D printing, which directly embeds soft materials within rigid panels to form soft creases. We use fixed‐stiffness inserts (FSIs) to set predetermined stiffnesses or variable‐stiffness inserts (VSIs) to tune the stiffness on‐the‐fly. Tendon‐driven actuation transmits motor‐driven displacement through routed cables to selectively fold targeted creases. A simplified analytical model based on geometry and cable tension analysis predicts crease bending under prescribed tendon displacements, and experimental validation confirms the model's accuracy across representative stiffness configurations. Using this framework, we demonstrate a three‐fingered origami robot grasping objects with diverse geometries and weights through different stiffness patterns and executing two locomotion gaits (crawling and crutching) with gait switching enabled by a single VSI. The results show that stiffness programming provides a compact mechanism for versatile origami robots capable of adaptive motion.