2016/05/31 by Neil Y. C. Lin, Christopher Ness, Michael E. Cates +2 · 1 citation
Chemical Engineering · Engineering · Materials Science · Physics and Astronomy · #Composite material #Dilatant #Granular flow and fluidized beds #Material Dynamics and Properties #Materials science #Mechanics #Physics #Polymer science #Rheology and Fluid Dynamics Studies #Shear (geology) #Shear flow #Shear rate #Shearing (physics) #Thickening #Viscosity #cond-mat.mtrl-sci #cond-mat.soft #physics.flu-dyn
paper · pdf · doi:10.1073/pnas.1608348113
in PNAS (2016)
arxiv created 2016/09/01 · openalex publication_date 2016/09/12 · arxiv updated 2017/02/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Shear thickening, an increase of viscosity with shear rate, is a ubiquitous phenomenon in suspended materials that has implications for broad technological applications. Controlling this thickening behavior remains a major challenge and has led to empirical strategies ranging from altering the particle surfaces and shape to modifying the solvent properties. However, none of these methods allows for tuning of flow properties during shear itself. Here, we demonstrate that by strategic imposition of a high-frequency and low-amplitude shear perturbation orthogonal to the primary shearing flow, we can largely eradicate shear thickening. The orthogonal shear effectively becomes a regulator for controlling thickening in the suspension, allowing the viscosity to be reduced by up to 2 decades on demand. In a separate setup, we show that such effects can be induced by simply agitating the sample transversely to the primary shear direction. Overall, the ability of in situ manipulation of shear thickening paves a route toward creating materials whose mechanical properties can be controlled.