Transition Wave-driven Sequential Actuation Provides Functionality to Soft Robotic Systems*

Soft robotic systems that rely on fluidic actuation are great candidates for producing sophisticated motions harnessing their inherent structural and material compliance. In most applications, soft robots are able to attain complex motions through the individual actuation of their constituent fluidic actuators. However, this results in multiple input lines connected to separate pressure supplies and a complex actuation process. In this study, we harness transition waves in bistable structures to dramatically simplify the actuation of soft robotic systems. Through a combination of experiments and numerical simulations we demonstrate that the transition waves propagating in a system comprising several bistable dome-shaped membranes that enclose fluid filled cavities can be exploited to trigger the sequential actuation of deformable actuators, producing a complex preprogrammed response with just a single and simple input.