A Bricard-inspired origami chamber for wide-range pneumatic rotary actuation in rigid–soft hybrid fingers

Rigid–soft hybrid robotic hands offer advantages in dexterous manipulation, adaptive grasping, and safe physical interaction. However, hand-scale rigid–soft hybrid fingers remain difficult to design because they lack a soft actuator that simultaneously provides compact size, stable motion, and wide-range actuation. In this article, a Bricard-inspired pneumatic origami chamber is proposed to achieve low dissipation, high repeatability, and compact rotary output. Its Bricard-inspired geometry enables wide-range rotary motion within a compact 15 mm × 20 mm cross-section. Fiber-reinforced fabric reduces energy dissipation, while rigid panels of the origami chamber impose geometric constraints and suppress parasitic deformation. Kinematically equivalent and quasi-static models are established to describe the chamber volume variation and the torque–angle–pressure relationship. Experiments show that the chamber achieves stable rotary motion over a wide range. Furthermore, the chamber is integrated into a rigid–soft hybrid finger. Prototype design, modeling, and experiments verify the integrated actuation capability of the finger, while rapid grasping and fine manipulation demonstrations show its application potential.