Design and development of a soft robotic manipulator

Soft robotic manipulator, which has advantages of low-weight, flexibility, safe physical interaction, shows a wide prospect in both industry and family application. In this paper, a design of pneumatic soft manipulator, in which the modularization concept is adopted, is presented. The soft manipulator is made up of three pneumatic soft actuators stacked in series. The soft actuator is composed of three inflatable bellows, which are connected and constrained by a series of thin rigid plates. The bellows is stretched by the actuation of pressured gas. The cooperation of the bellows and the rigid constraints effect the soft actuator's directional move. The stacking connection of several soft actuators can have a large coverage in space. Based on this design, the kinematic models of the soft actuator as well as the soft manipulator are proposed using piecewise constant curvature method. The elastic coefficient of the actuator, which is necessary in the numerical calculation of the proposed model, is determined experimentally. Finally, the prototype and experimental set up of the soft manipulator are designed and developed. The correctness of the proposed model and the end-repeat positioning accuracy are validated experimentally.