Clogging in fluidic systems: the self-sabotage of suspensions*

From pipes to highways to medical devices, stopping the flow is always inconvenient and sometimes dangerous. Clogging can occur in confined flows of particulate suspension that are carrying either too many particles or particles that are too large or sticky. As a result, clogging is problematic in many engineering systems. For instance, the blockage of inkjet printer nozzles or the progressive clogging of irrigation systems by colloidal particles impairs their performance. Similarly, the frequent formation of clogs in nozzles used to dispense fiber-filled polymer inks in extrusion-based additive manufacturing processes limits the concentration of fibers that can be used in three-dimensional printing.

The challenge in studying the clogging of fluid systems by suspensions is that the underlying physics is complex and spans many length scales (from bacteria to boulders) and time scales (from less than a second to years). In this talk, we will discuss how and why flowing stuff gets stuck. In particular, we will highlight the role of the different clogging mechanisms at play in various systems and our recent efforts to characterize, model, and prevent - or at least delay - the clogging of fluidic systems. We will also consider different potential methods to limit clogging in some applications. Predicting when clogging is likely to occur and working to prevent it can lead to new design principles to develop clog-resilient systems and improve the reliability of fluidic systems dispensing particulate suspensions.