Variations of dielectric and resistive responses of a material with deformation are called dielectrostriction and piezoresistance respectively. Both phenomena have the same microscopic foundation — they involve the change of relative positions of polarizable or conductive species, leading to change in the material’s electric properties. Since both dielectrostriction and piezoresistance are determined by the pair distribution function of inclusions, these two phenomena are sensitive to a material’s microstructure, which renders them effective for monitoring liquid polymer and polymer suspension processing and mixing. In this study, a planar sensor is implemented to detect the dielectrostriction effect in shear flow of pure silicone elastomer and piezoresistance effect in silicone/graphite suspensions. In both measurements, the electric responses are found to be scaled with the flow-induced stresses, which constitute new approaches to study the rheological properties of bulk materials and suspensions and compliment each other for revealing the microstructure in various systems.
Rheological properties for inelastic Maxwell mixtures under shear flow
