Soft manipulator inspired by octopi: object grasping in all anatomical planes using a tendon-driven continuum arm

In this paper, we focus on the development of a soft continuum arm manipulator inspired by the morphology of octopi and their intelligent behavior. The proposed arm is mainly composed of soft silicone rubber material, offering high levels of arm deformation and flexibility of movement. Tendon-like actuator strings are incorporated inside the arm to generate motion. Using a pulling mechanism of the actuating strings, the arm mimics octopi's behavior by performing five different motions in all three body planes: lateral right and lateral left motion in the sagittal plane, ventral and dorsal motion in the coronal plane, and helical torsion motion in the transverse plane. The proposed soft arm can grasp, move, and lift various hard and soft objects, without previous sensing nor the usage of suction cups, making it a powerful low-complexity tool for object manipulation in complex environments.