Modeling and Analysis of Soft Pneumatic Network Bending Actuators

This article presents an analytical model for soft pneumatic network actuators (PneuNets) consisting of a series of chambers made of elastomeric material and an inextensible bottom layer. The model links the input pressure with the bending angle in free space and the tip force of the PneuNets. The bending principle of the PneuNets is comprehensively analyzed through the analytical model. The bending angle of PneuNets is analyzed considering the deflection of the gap layer. The tip force of PneuNets is analyzed considering the equilibrium moment of the PneuNets at the applied pressure. This article focuses on the deformation of the gap layer of the PneuNets and the effect of gap length on the bending angle. The proposed model considers the deformation of the lateral wall of the chamber as the deformation of the nonlinear hyperelastic membrane. Futhermore, the contact moment is included considering the Hertzian contact between the adjacent chambers. Finite element analysis and physical experiments are carried out and the results show that the bending angle and tip force of the PneuNets can be effectively predicted by the analytical model with an error of less than 10%.