Soft, Fiber-Reinforced Bellow Actuators

Stacked balloon actuators, constructed from heat- and pressure-bonded, stacked layers of sheet films have demonstrated their utility in soft robotics for performing intricate tasks and adapting to space-constrained environments. However, these actuators face limitations such as reduced force output at low displacement heights due to buckling and small retractive forces at high displacement heights due to radial collapse under vacuum. To mitigate these issues, we introduce a method for integrating fiber reinforcements: a nylon mesh fabric that increases the tensile strength of the actuator's structural layers without constraining the maximum inflated height, and a heat-sealable nylon taffeta fabric that provides radial support to the actuator's multi-chamber design. We demonstrate the advantages of this approach in a quadruped soft robot, showcasing improved force output, actuation speed, and the advantageous use of actuator's collapsibility for shape morphing.