Architectures of soft pneumatic actuators for wearable human assistive applications

Abstract

This thesis presents the design and analysis of two novel fabric-like architectures of soft pneumatic actuators known as Fiber Reinforced Elastomeric Enclosures (FREEs) and studies the implication of wearing them as sleeves around the elbow joint. The first architecture is a helical arrangement of FREEs, which is shown to directionally modulate its stiffness. The second architecture is a nested arrangement of FREEs, which is shown to provide 70% more actuation stroke than a single actuator. The thesis presents an analytical framework, first to accurately capture the behavior of a contracting FREE actuator, and then the model stiffness modulation and stroke amplification functionalities of the two architectures. These models are verified with both benchtop experiments and preliminary human testing. The thesis presents design guidelines to configure these architectures for any functional and size requirements.