Shear-induced mechanical anisotropy in concentrated emulsions: a pump probe mechanical spectroscopy study

Concentrated suspensions develop an anisotropic microstructure when subjected to deformation, and this anisotropy persists after flow cessation, leading to direction-dependent mechanical properties. We investigate the mechanical response of a concentrated emulsion following an initial shear deformation. We use a circularly polarized shear to probe the material's elasticity in all directions relative to the initial shear. The emulsion softens along the direction of the applied deformation and stiffens in the perpendicular direction. The degree of mechanical anisotropy is found to depend on the amplitude of the initial deformation, with larger deformations leading to more pronounced directional differences in elasticity.