Design and Modelling of an Expandable Bending Actuator with Multiple Pneumatic Sources

Abstract This paper describes the design and modeling of an inflatable bending actuator with multiple pneumatic sources. The actuator features independent pneumatic modules sewn onto a flexible, inextensible fabric structure. The bladders of the actuator comprise the maintaining layer with constant pressure and the driving layer with adjustable pressure. The active state of the actuator can be altered by adjusting the pressure of the driving layer, while varying the number of driving layers can lead to different operational modes. Compared to other soft actuators, the actuator in this paper has better load capacity at low pressures and superior response performance. We created a mathematical model to forecast the output torque. Finally, we examine the impact of modifying the actuator pneumatic supply mode on both the functionality and operational state of the actuator and test its dynamic performance. Additionally, we verify that the output torque performance of the actuator remains stable.