A New Systematic Inverse Design Method of Pneumatic Soft Actuator for Precise Motion

Abstract

This study presents a design method for pneumatic soft actuators, guaranteeing precise actuator kinematics. Unlike conventional soft actuator designs, which rely on trial-and-error or heuristic modeling, our approach allows direct inverse derivation of uninflated actuator geometry from the desired post-actuation shape. Additionally, its modular nature enables the creation of compact actuators optimized for maximum bending angles. Using surface curvature principles, the method leverages a pseudo-dynamics algorithm to efficiently compute the optimal actuator geometry with minimal computational cost. To validate our method, we fabricated and tested modular actuators with diverse actuation capabilities. Results confirmed that each actuator reliably achieved the intended target shapes. Furthermore, using these modular actuators, a three-finger gripper was constructed, demonstrating precise grasping of objects with complex geometries. This work establishes a robust and scalable framework for designing pneumatic soft actuators with predictable kinematics.