Origami-inspired soft twisting actuator

TL;DR

This paper introduces origami-inspired soft pneumatic actuators made from silicone that can produce significant torsional motion, enabling advanced manipulation tasks in soft robotics.

Contribution

It presents a novel design, fabrication, and analytical modeling of silicone-based soft twisting actuators with high rotation capacity and efficiency.

Findings

Achieved rotation of over 435 degrees in prototypes

Rotation ratio exceeds 136 degrees per aspect ratio, doubling previous records

Demonstrated versatile applications in soft grippers, robot arms, and snake robots

Abstract

Soft actuators have shown great advantages in compliance and morphology matched for manipulation of delicate objects and inspection in a confined space. There is an unmet need for a soft actuator that can provide torsional motion to e.g. enlarge working space and increase degrees of freedom. Towards this goal, we present origami-inspired soft pneumatic actuators (OSPAs) made from silicone. The prototype can output a rotation of more than one revolution (up to 435{\deg}), more significant than its counterparts. Its rotation ratio (=rotation angle/ aspect ratio) is more than 136{\deg}, about twice the largest one in other literature. We describe the design and fabrication method, build the analytical model and simulation model, and analyze and optimize the parameters. Finally, we demonstrate the potentially extensive utility of the OSPAs through their integration into a gripper capable of simultaneously grasping and lifting fragile or flat objects, a versatile robot arm capable of picking and placing items at the right angle with the twisting actuators, and a soft snake robot capable of changing attitude and directions by torsion of the twisting actuators.