Soft Mini Fuse Valve for Resilient Fluidically-Actuated Robots

Abstract

Lately, soft fluidic actuation has gained widespread interest in all fields where compliance and adaptability are the main keywords. Despite their well-known advantages, soft fluidic actuators frequently present problems related to the elastomeric chambers' durability, affecting the overall system robustness and safety. Indeed, if a robot relies on the parallel pressurisation of multiple actuators, the burst of a single chamber leads to the failure of the entire fluidic circuit, with consequent potentially hazardous leaks. Here, we present the development of a Soft Mini-Fuse (SMIF) valve able to secure and maintain the system functionality even in case of burst failure of single components without affecting their overall bulkiness. By modelling the valve through both analytical and finite element tools, we defined the correlation between main geometrical features, material properties and a selected range of blocking pressures (0.1-1.0 bar). Finally, after validating the modelling tools, we characterised the device behaviour in a range of commonly employed actuation flows (0-15 l/min). The compact dimensions, the ease of integration and the demonstrated performances underline that the SMIF valve represents a novel valuable ally that guarantees stable actuation, limits human intervention and paves the way towards more resilient and autonomous soft fluidic robotic systems.