Fascinating rheological properties like shear thickening/thinning and anisotropic viscosity arise from underlying structure in complex fluids. We develop and use techniques to simultaneously analyze emergent, large-scale properties and image particle-level positions and stresses in such suspensions.
Shear thickening fluids like mixtures of cornstarch and water, or oobleck, are not only fun to play with but also have applications ranging from 3D printing to body armor and shock absorption. However, the rapid increase in the viscosity with the shear rate, the very property that makes these suspensions so interesting for industrial applications also leads to jamming and failure of processing equipment. Thus, it is essential to find a method to control and tune the viscosity of these shear thickening suspensions.
Here we discuss the various methods that we are working on to tune the viscosity of these shear thickening suspensions.
Understanding the flow of complex fluids through confined spaces and forces governing the flow is key to diverse fields, from blood flow to lubricant design. Studying such situations is difficult because typical devices cannot achieve the necessary degree of confinement. New experiments and simulations reveal flow behavior under different levels of confinement and show how this behavior can be tuned.