Electroosmotic Flow of Two Eyring Fluids in a Microchannel Under Non-Newtonian Hydrodynamic Slip Conditions

Because of the fast technological advancement that has occurred in recent years in the area of MEMS (Micro- Electro- MechanicalSystems), materials that were not previously considered for their use are now emerging as validated manufacturing options. Among these materials, hydrophobic polymers stand out due to the relationship between the material's hydrophobicity and the sliding velocity that the fluid develops on the microchannel wall. This phenomenon, known as slip velocity, which we now know occurs on the microscale, has been relatively underexplored in the literature. It is for this reason that the present research focuses on the flow of two non-Newtonian, immiscible and completely developed fluids in a microchannel of parallel flat plates generated by electroosmosis. The mathematical model for the characterization of the steady-state flow field is based on the Poisson-Boltzmann equation and the Cauchy momentum equation. Each fluid has independent electrical and physical properties and is composed of a mixture between a fluid that exhibits viscoelastic behaviour following the Eyring fluid rheological model and an electrolyte. In this case, the microchannel walls are dielectric and the fluids are conductive, resulting in electric double layers at the liquid-liquid and solid- liquid interfaces. As a result, the flow field is governed by interfacial electrostatic conditions, and Navier slip conditions are considered based on the selected rheological model. The analytical results are centered on the description the velocity profiles as a function of a set of dimensionless parameters arising from the mathematical characterization. “