A comparison of plane, slow pneu-net, and fast pneu-net designs of soft pneumatic actuators based on bending behavior

Abstract

Soft robots are developed getting inspired by the bio-living organism. These robots require soft actuators such as pneumatic, hydraulic, electro-active polymer and shape-memory materials for their actuations. Out of these actuators, soft pneumatic actuators (SPAs) are the most commonly utilized actuators due to their lightweight and high output at very low actuating pressure. SPAs are developed using hyperelastic materials such as silicon rubber; some commercially available hyperelastic materials are ecoflex, dragon skin, and elastosil. The present work focuses on analyzing three different designs of SPAs considering ecoflex material. The mechanical properties of ecoflex are evaluated experimentally. Three SPAs designs including plane, soft pneu-net (sPN), and fast pneu-net (fPN) are computationally analyzed and compared based on their bending behavior under similar loading and boundary conditions. For computational analysis, finite element theory is utilized considering the Ogden model for hyperelastic materials. Obtained simulation results depict that for similar loading and boundary conditions, the SPA with fPN design creates a larger bending angle compared to plane and sPN designs.