In the industry, only a few smart materials are used due to the extensive study they require in order to predict their behavior. The magnetorheological fluids (MRF) are one of the most commonly used. In the scope of this thesis, the MRF with the following composition were studied: oil, carbonyl iron particles of micrometer size and chemicals called surfactants to help the iron particles to stay in suspension in the oil. The goal of this project was to provide a model which links the magnetic and fluidic properties of the MRF by analyzing the structures created by the iron particles in the fluid. These structures are created when a magnetic field is applied, to guide it through the channel. Their creation changes the rheological properties of the MRF. But when a mechanical stress is applied on them, they deform and thus disturb the magnetic field. The model presented in this thesis allows to quantify these effects and use the MRF for the variation of their rheological properties, as in a valve for example, but also as sensors for pressure and flow. A setup was created to measure all the effects simultaneously and all the difficulties encountered during the design and prototyping are discussed in the thesis for future improvement. Finally, the measurements along with the models allowed to reveal and quantify several effect occurring with the use of MRF and provided a base to the future designs of valves with self-sensing properties.