Modeling, Characterization, and Application of Soft Bellows-Type Pneumatic Actuators for Bionic Locomotion

Soft bellows-type pneumatic actuators (SBPAs), which consist of two cavities with small chambers embedded in elastomeric structures, are an essential embranchment in the field of soft actuators. However, more analytical modeling and analysis of SBPAs need to be studied. In this article, we first present the structure design, fabrication method, and material property test of the SBPA. Then, based on the plate bending theory, an analytical model and the corresponding design approach for SBPAs are established, which consider both geometric complexity and material nonlinearity. The verification results indicate that the predicted analytical results coincide well with the physical experimental measurement and simulation results. The decision coefficient is R² = 0.9720. The impacts of geometric dimensions and silicone material characteristics on the bending deformation of SBPAs are also explored. We further demonstrate the bionic utility of SBPAs. Such an approach can be used as a tool for the design optimization of bellows-type actuators and save the designer lots of finite element analysis with its low computational cost. This work provides a detailed investigation of the performance of SBPAs, which can be a basic module for various types of soft robots such as soft snake robots, crawling robots, and robotic arms in the future.