Origami-inspired bi-directional soft pneumatic actuator with integrated variable stiffness mechanism

The field of soft robotics has a wide array of applications, particularly in human-robotic interaction, from medical devices to assembly technology. In this paper, we introduce a novel design for a soft bi-directional pneumatic actuator inspired by the principles of origami. The actuator integrates a variable stiffness application using a layer jamming mechanism (LJM). LJM utilizes the effects of negative pressure on thin layers of material, providing rigidity. Incorporated into an origami bellows structure, the negative pressure causes both contractile action and stiffness, while extensive action is caused by an internal pneumatic chamber, allowing for contractile and extensive force application. Furthermore, the variable stiffness integration improved tensile force application threefold, resistance to outside linear force tenfold, and doubled sheer force resistance. The proposed origami-inspired bi-directional soft pneumatic soft actuator has immense potential to be implemented in complex biomedical applications in the near future.