Magnetic wire-based sensors for the micro-rheology of complex fluids

摘要

We propose a simple micro-rheology technique to evaluate the viscoelasticproperties of complex fluids. The method is based on the use of magnetic wiresof a few microns in length submitted to a rotational magnetic field. In thiswork, the method is implemented on a surfactant wormlike micellar solution thatbehaves as an ideal Maxwell fluid. With increasing frequency, the wires undergoa transition between a steady and a hindered rotation regime. The study showsthat the average rotational velocity and the amplitudes of the oscillationsobey scaling laws with well-defined exponents. From a comparison between modelpredictions and experiments, the rheological parameters of the fluid aredetermined.