Endowing Soft Robots with Fluidic Counting

Perception and remembering the number of events is a crucial feature for living systems. Such features fundamentally contribute to the autonomy and intelligence of beings in the whole Eukaryota. Counting in soft robotics is typically achieved by sensing mechanical and/or fluidic changes in the system through electric signals captured by dedicated sensors.

Although useful for accurate estimates and fast response times, such a strategy imposes additional complexity in both hardware and software that often undermines the simplicity, resistance of the soft robotic unit.

With the goal to allow soft robots to be autonomous and resilient, we present a smart fluidic circuit that paves the way to such features with no need of electronics.

Our fluidic circuit is based on a soft hysteretic valve combined with kinking tubes, that can be used as a discrete event counter in soft robots.

We demonstrate our strategy with two case studies. First, when controlled in flow, our design results in a discrete clock that can be used to define different programmes in soft robots. Secondly, when the very same circuit is used in pressure control, external events can trigger our circuit and result in a fully soft fluidic event counter. Not only does our proposed design allow for discrete binary counting that can be easily remapped to traditional binary logic, it also can be used for counting in a non-binary base, keeping the same fluidic circuit.