Design and Modularization of Multi-DoF Soft Robotic Actuators

Abstract

Soft robotic technologies offer a promising solution for unconstructed applications due to their complete softness, robustness, and flexibility. In this letter, we explore the design and modularization of the flexible pneumatic robotic actuators for applying in minimally invasive surgery or other constrained spaces. We first identify the basic multi-cavity structure and subsequently explore three basic morphologies of the multi-degree of freedom (DoF) actuator, which are differentiated by the shapes of their inner chambers. The corresponding fabrication methods are developed to create standard fabrication processes for such complicated structures. Furthermore, we propose the modular concept and method of assembling these actuators into flexible robotic manipulators for different applications. Results show that the fabrication methods are suitable for the corresponding different chamber structures and are adaptive for fabricating multiple scales from the miniature size (diameter of 3.5 mm) to larger size. Detailed characterizations show that the multi-DoF actuators can freely adjust their heading direction in the three-dimensional space. Additionally, application experiments show that the modular design achieves to rapidly assemble flexible robotic manipulators, which are potential in future applications that require closer inspection and manipulation.