Grasping by wrapping: Mechanical design and evaluation

Abstract

This paper presents an analysis of the design and operation of a non-articulated robotic hand, inspired by the multilayered structure. The hand is made of a non-stretchable thin film, the two ends of which are attached to a soft substrate, forming an enclosed wrinkled shape. When the substrate is elongated, the morphology of the hand changes varied, resulting in a “wrapping” form around the grasped object. This design is applicable to a wide range of objects that can be grasped by the robotic hand. The smallest and biggest sizes of the grasped object are determined by the morphological computation of the film during design of the hand. This design also reduces the uncertainty of position between the hand and the object; i.e., stable grasping can be maintained as long as the object fits within the enclosed form of the hand. A mechanism controlling the morphology of the film using only one actuator, and for grasping food products such as fruits, is proposed. Preliminary results show the potential of the hand's morphology in the design of soft robotic mechanisms.