Generalized Delta Mechanisms from Soft Actuators

Abstract

Soft robots, and more specifically soft actuators, have the promise to create high degree of freedom actuation. However, designing these actuators to achieve complex motions is difficult. Here we propose the design of a soft mechanism class that can be additively manufactured and easily and intuitively designed. The actuators use parallel structures of simple soft linear-extension actuators to create higher degree of freedom movements without additional joints or mechanical components. We show that depending on configuration, the actuators can be designed to create pure planer motion, motion in 3-space, and rotation. We also analyze the position and force workspaces for a set of designs, comparing outputs across linear scaling and number of simple actuators. Lastly, we show a demonstration in distributed locomotion that highlights the ease of manufacturing and the use of the large number of controllable degrees of freedom.