Optoelectronically Innervated Suction Cup Inspired by the Octopus

The suckers on the octopus arm play a pivotal role in the execution of tasks in unstructured environments by providing a means to grip objects as well as perceive the environment through (chemo-)tactile receptors in the suckers. This work presents an octopus-inspired suction cup with high-resolution tactile sensing capabilities using a camera that captures the displacement of markers that are integrated in the suction cup. The orientation of the suction cup with respect to an object surface could be predicted with an average error of 1.97° for latitude and 9.41° for longitude. In a closed-loop control experiment, the orientation of the suction cup with respect to the object surface is estimated by an initial touch and the suction cup is consequently reoriented to approach the object surface in a perpendicular manner. The passive compliance of the suction cup is sufficient to compensate for the prediction error and a seal could be created on all of the objects. In combination with the automated design and manufacturing process, this is a major step toward the deployment of sensory innervated suction cups for motion planning and control of soft continuum robot arms.