Biologically inspired tri-directional soft pneumatic actuators: design, modeling and multi-scenario soft robotic applications

Abstract Currently, soft pneumatic actuators are widely used in the field of soft robotics. However, the majority of them are designed for specific application scenarios. To broaden the practical applications of a single actuator and tackle the issue of actuator versatility, this paper introduces the design of a bionic multidirectional bending actuator inspired by the tail structure of a crocodile. The actuator offers cost-effectiveness, responsiveness, adaptability, and sideways rotation capability. The research utilizes a modular approach that allows the actuator to be constructed and assembled into mechanical soft grippers, assistive gloves, and bipedal crawling robots. Based on various application scenarios, this study has designed three basic bending gaits that enable a mechanical gripper to grasp objects, unscrew bottle caps, assist the hand in grasping and placing objects, and enable the robot to crawl forward and turn, respectively. Overall, the actuators proposed in this paper are highly adaptable to a variety of applications and can reliably fulfil the required tasks.