A Soft Underwater End-Effector

Abstract

Current underwater end-effector technology has limits in terms of finesse and versatility. Because of this, the execution of several underwater operations - as archaeological recovery and biological sampling - often still requires direct intervention of human operators, exposing them to the risks of working in a difficult environment. This paper proposes the design and implementation of an under-actuated and compliant underwater end-effector, which embodies both grasp capabilities comparable to those of a scuba’s real hand and the large grasping envelope of grippers. The proposed end-effector, whose design is based on the the Pisa/IIT SoftHand, is composed of a modular watertight chamber with pressure compensation - hosting the electronics and motor - and of a set of two soft terminal devices which implement an adaptive grasping function. Field results, obtained with the end-effector controlled underwater by a human operator (10 meters depth), show good grasping performance in both dexterity and force tasks.