Bubble casting soft robotics

International audienceInspired by living organisms, soft robots are developed from intrinsically compliant materials enabling con-tinuous motions mimicking animal and vegetal movement. In soft robots, the canonical hinges and bolts arereplaced by elastomers assembled into actuators programmed to change shape following the application of stimuli,e.g. pneumatic inflation. The morphing information is typically directly embedded within the shape of theseactuators, whose assembly is facilitated by recent advances in rapid prototyping techniques. Yet, thesemanufacturing processes have limitations in scalability, design flexibility and robustness. Here we demonstratea new all-in-one methodology for the fabrication and the programming of soft machines. Instead of relying onthe assembly of individual parts, our approach harnesses interfacial flows in elastomers that progressively cure torobustly produce monolithic pneumatic actuators whose shape can easily be tailored to suit applications rangingfrom artificial muscles to grippers. We rationalize the fluid mechanics at play in the assembly of our actuators andmodel their subsequent morphing. We leverage this quantitative knowledge to program these soft machines andproduce complex functionalities, e.g. sequential motion obtained from a monotonic stimulus. We expect that theflexibility, robustness and predictive nature of our methodology will accelerate the proliferation of soft robotics byenabling the assembly of complex actuators, e.g. long, tortuous or vascular structures, thereby paving the waytowards new functionalities stemming from geometric and material nonlinearities