A novel inclined membrane contact model for analyzing the pneu-net soft actuator lateral wall contact

Abstract

Pneu-net soft actuators are widely used in the soft robotics society owing to their light weight, high deformation, and fast response. This paper presents a novel theoretical framework to model the static analysis and contact mechanics of pneumatic soft actuators undergoing large deformations. While most soft robots exhibit complex material behaviors, we show that their mechanics can be accurately captured through the fundamental principles of elasticity and contact theories. The core contribution is an inclined membrane contact model that elegantly transforms the complex three-dimensional contact between angled surfaces into an equivalent problem of horizontal contact, enabling the use of established contact solutions. This model is integrated with an energy-based solution for elastic deformation to fully characterize soft actuator bending. The generalizable modeling approach is applied to the example of a pneumatic net actuator, with comprehensive validation against finite element analysis and experiments. This work advances a fundamental understanding of soft machine statics and contact mechanics while providing an analytical tool for the design and control of deformable actuators. The flexible theoretical framework presented can be extended to diverse interdisciplinary problems involving moving surfaces in contact.