Design and Modeling of a Hybrid Soft Robotic Manipulator With Compliant Mechanism

The recent surge of interest in soft robotics has prompted many interesting soft robotic manipulator designs to be proposed. However, current soft robotic manipulators mainly focus on bending and rotation, while elongation has not received attention due to the limited extension/contraction range or the inextensibility of the backbone. This will adversely affect the application of soft robotic manipulators. In this letter, we introduce a hybrid soft robotic manipulator capable of controllable elongation and give a modeling method based on equilibrium principles and assuming a priori deformed configuration. The hybrid soft manipulator consists of a multi-chamber soft body and a rod-driven compliant mechanism, wherein the compliant mechanism provides a push-pull drive to constrain the motion of the manipulator. The model is a modeling framework for a multi-chamber soft robotic manipulator that depicts the relationship between pressures, bending, rotation, and elongation. We experimentally verify the model and demonstrate the potential of the hybrid soft manipulator for point tracking, by comparing it with the soft manipulator without driving rods.