Design of self-deployable origami utilizing rigid-elastic coupling spherical mechanism

Origami-inspired mechanisms are extensively utilized in aerospace, medical devices, and soft robotics due to their simplicity, reliability, and high fold-to-deploy ratio. However, actuating these structures for deployment remains challenging. This paper presents a design method for self-deployable origami utilizing the rigid-elastic coupling spherical mechanism. Initially, the rigid-elastic coupling spherical mechanism is designed by replacing one revolute joint of the rigid spherical mechanism with a V-shaped elastic nickel–titanium (Ni–Ti) alloy wire. We show that the rigid-elastic coupling spherical mechanism has equivalent kinematics to the associated rigid spherical mechanism, which is also the equivalent mechanism of the rigid-elastic coupling origami unit. By leveraging the elastic deformation of the Ni–Ti alloy wire in conjunction with the motion of the revolute joints, the rigid-elastic coupling mechanism acquires bistable characteristics, thereby enabling shape memory for self-deployment. The typical origami patterns, such as Miura-ori and Yoshimura-ori, are employed as design examples to showcase the performances of the associated self-deployable origami.