From pipes to aquifers to medical devices, stopping the flow is always inconvenient and sometimes dangerous. Clogging can occur in confined flows of particulate suspensions when particles are too numerous, too large, or too sticky. It poses challenges in many engineering systems, including printer nozzles, drip irrigation lines, autoinjection devices, and pipes.

Understanding suspension clogging is difficult because the underlying physics spans many length scales, from colloids 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. We will examine the different clogging mechanisms at play in various systems and present our recent efforts to characterize, model, and prevent, or at least delay, the clogging of fluidic systems. We will also discuss practical approaches to limiting clogging in some applications. Understanding when and how clogs form can guide the design of more reliable systems for transporting and dispensing particulate suspensions.