Abstract: In order to efficiently design a three-dimensional pneumatic soft actuator with flexible and excellent bending performance, the bending mechanism of the actuator are studied for the single-chamber structure. Based on the energy density distribution function of the Yeoh model, combining with the static equilibrium equation of the actuator bending, a nonlinear mathematical model between the actuating pressure and the bending angle of the actuator is established. Secondly, the chamber radius, the central circle radius and the wall thickness which effect on bending are analyzed by the mathematical model that searching the optimal size combination of them using the single-objective multi-constraint optimization model. Then, the variation of the bending angle, deflection angle and end point coordinates of the actuator with the two-chamber ventilation is further studied by finite element simulation. Finally, comparing the data of theoretical model, finite element simulation and prototype experiment, it shows that the theoretical results, simulation results and experimental results are basically consistent in the range of 0-60 kPa, which verifies the correctness of the theoretical model. The above studies provide a reliable theoretical basis for designing pneumatic soft bending actuators.

Key words: pneumatic soft actuator, bending performance, deformation model, optimization design, finite element simulation