Coupled, closed-system fluidic actuators for use in wearable rehabilitation devices

This paper presents a novel closed-system, coupled soft actuator that aims to increase the applied bending moment that can be powered by a single pneumatic pump. The actuator incorporates both positive pressure and vacuum actuators of established design. The purpose of this development is to enable the design of an effective soft robotic wearable device for the re-habilitation of the revolute joints in post-stroke individuals. The design of a test rig to provide consistent, quantitative data on the output of the soft actuators is presented, allowing a comparison of the positive pressure, vacuum and combined (positive and vacuum) actuators. This combination demonstrates the ability to significantly increase the torque output when compared to a single actuator using the same pump for input, potentially reducing the weight of a wearable device. The closed-system, coupled soft actuator system shows opportunity for use in a wide range of applications due to this reduction in pump weight and isolation from environmental conditions.