Design of Gusseted Pouch Motors for Improved Soft Pneumatic Actuation

The performance of soft robots depends in large part on the actuation performance of the soft actuators used to drive them, and those making use of fluidic actuation have gained the most traction in the form of pneumatic artificial muscles (PAMs). These PAMs make use of the change in volume of a structure through pressurization of their volume to produce mechanical work. However, their performance depends in large part on how this volume deforms throughout the motion. Pouch motors have been proposed as a lightweight yet powerful soft actuator, but their sealed ends limit their performance. This article proposed the addition of gussets onto pouch motors to form gusseted pouch motors for improved performance. This allows for the actuator to produce a larger contraction ratio than without gussets and allows for the force to increase as the length of the actuator increases. This article explains the manufacturing of the actuator, proposes a numerical model that predicts well the performance of the actuator, shows experimental results for different actuator dimensions, and provides a comparison with regular pouch motors. It then demonstrates stiffness control using antagonistic pouch motors and implements the actuator into a simple robotic arm with angular position control.