High-force soft pneumatic actuators based on novel casting method for robotic applications

Abstract

Soft pneumatic actuators (SPAs) play an important role in leading the development of soft robotics, and enable diverse and complex hardware design for soft robots. However, due to the limitation of the inherent characteristics of SPAs’ constitutive materials as well as fabrication tools and techniques, they tend to exhibit a lower driving force. In this paper, we propose a class of high-force SPAs that are fabricated by a novel method, embedded core casting. This method is enabled by two main steps: First, a SPA is designed in two parts, an actuating core composed of a fiber-reinforced airbag and an elastic holder made of soft materials, and they are fabricated independently; second, both parts are combined together by assembly and recasting techniques, producing a finished actuator. The bending SPAs fabricated by this method can bear air pressure up to 400 kPa, which provides important hardware for the development of high-load soft robots. Further, we demonstrate the applications of these soft SPAs in soft grippers, continuum manipulators, and soft wearable robots. This study helps improve the fabrication process for fiber-reinforced actuators and propose new high-force SPAs for robotic applications.