Fluidical bending actuator designed for soft octopus robot tentacle

Soft actuation, due to its mechanical properties offer a complex motion that is not achievable for traditional mechanism. Thanks to that property it is often considered for bio-mimicking devices as many leaving creatures move by complex and distributed deformation. In this paper we propose a novel soft fluidical actuator designed to be used as a biomimicking tentacle in swimming octopus robot. The actuator has two degrees of freedom that enables bending in some range of directions and inherits the actuation effectiveness of single degree of freedom actuators while still able to control two of them. The actuator has been tested in terms of generated forces and motion capabilities and shows significant improvement regarding the state of the art actuators capable of completing the assumed task. The actuator enables the octopus robot to advance forward, change swimming directions and rotate around its primary axis. The paper presents the design, fabrication process and experimental verification of the proposed solution.