Concentrated Suspensions Under Flow: Shear-Thickening and Jamming

When a concentrated suspension of colloidal particles is sheared at high enough shear rates, its viscosity increases with the shear rate. Depending on the details of the interactions between particles, this increase may be continuous and the suspension is said to shear-thicken, or may be discontinuous, leading to an arrest of flow: the suspension jams. We review recent experimental evidence that both behaviors are the consequence of the formation of dynamical aggregates under flow.