Experimental study of single-chambered soft pneumatic actuator

This study aims to determine the ballooning and bending deformations of single-chambered soft pneumatic actuators (SPAs) under varying pneumatic pressures. Therefore, the SPA with 1 mm thick top wall is fabricated with Ecoflex-OO50 silicone rubber by employing 3D printing and casting technique. The fabricated single-chambered SPA is actuated with similar pneumatic pressures as in the case of FEA and it is found that the experimental results of SPA bending are closer to the FEA results. Additionally, the radial expansion or ballooning effect developed in the SPA is quantified in millimetres and plotted against the bending angles and varying actuating pressures. Thus, this study will help to thoroughly understand the bending and ballooning responses of single-chambered SPA under varying pneumatic pressures and further facilitates the refinement of analytical model to validate the experimental results. In the future, experiments could be performed to reduce ballooning of the SPA with the reinforcement of relatively stiffer but stretchable polymer membrane compared to the Ecoflex-OO50 silicone rubber. This will hopefully reduce ballooning and improves bending angles and contact forces, thus enhancing the single-chambered SPA performance for various soft robotic applications.