A Soft Growing Robot Using Hyperelastic Material

Abstract

Soft growing robots have received considerable attention because of their unique locomotion. However, the use of a single material for their manufacturing causes numerous problems, because each part of the robot requires different characteristics. This study attempts to solve this fundamental problem from a material perspective, rather than integrating independent solutions. A hyperelastic material is proposed for building a soft growing robot. Several problems associated with conventional soft growing robots are addressed using a hyperelastic material that offers the required properties for each part of the soft growing robot, while maintaining its intrinsic advantages. Two unique features of hyperelastic materials, bulging and shape-locking, are introduced. The advantages that these two features offer to soft growing robots are investigated and analyzed. A soft growing robot, utilizing these features, can easily achieve shape locking, small tail tension, easy retraction, uniform circular inner channel, and wrinkle-free curve formation, without additional hardware. The initial concept of the growing and steering mechanisms of a hyperelastic soft growing robot is proposed and demonstrated using a prototype.