In this work, a rheometer implemented on a chip is presented. The physical principle of this system is to use laminar Parallel Flows in a microfluidic channel. The fluid to study flows side by side with a reference fluid of known viscosity. By using optical microscopy, the shape of the interface between both fluids can be determined. Knowing the flow rates of the two liquids and the geometrical features of the channel, the mean shear rate sustained by the fluid and its viscosity can thus be computed. Accurate and precise rheological measurements of the entire rheological curve can be made using less than 300 microliters of fluid. Several complex fluids are tested with viscosities ranging from 10-3 to 70 Pa.s.
– Publié dans Langmuir