ASTRE: Prototyping Technique for Modular Soft Robots With Variable Stiffness

Abstract

Soft robots are advantageous for human interaction because of their adaptability and safe interactivity. However, soft robots research entry is challenging due to the complex fabrication process of elastomeric materials with multiple channels. In this paper, we introduce a prototyping technique for fabrication-friendly soft robots using pneumatic artificial muscle(PAMs) and modular 3D printed reinforcement. We present three primitive deformation structures including bending, twisting, and contracting. Moreover, we propose a novel variable stiffness technique, altering PAMs contraction and radial expansion behavior into locking, malleable, and rotational brake features. We explore both the parallel and series arrangement of the reinforcement module, and we propose new kinds of mixing configurations and scaling techniques. We quantitatively verify the force scaling technique on different types of features. We demonstrate the feasibility of this prototyping technique through six application examples and conclude with a discussion of our research limitations and possible future improvements.