Design and Characterisation of Cross-sectional Geometries for Soft Robotic Manipulators with Fibre-reinforced Chambers

Fluid elastomer actuators are a prevalent design paradigm in the field of soft robotics. To prevent the elastomer from ballooning and increase the actuation consistency, a fibre-reinforced design is commonly utilised, with the effect of the fibre angle on the robot's performance well established. However, the impact of the geometry of the fibre-reinforced chambers has not been tested. This paper explores two chamber geometries, circular and semi-circular, using measurements in alignment with minimally invasive surgery (MIS) to determine if there is a difference in performance. The fabrication process of robots with different chamber geometries is first streamlined, then the characterisation of each robot is experimentally identified. The results show the chamber geometry plays an important role in affecting the performance of the robots, e.g., with a stiffness variation greater than 20% between the two designs.