Magnetohydrodynamic Electroosmotic Flow With Patterned Charged Surface And Modulated Wettability In A Parallel Plate Microchannel

This paper investigates the magnetohydrodynamic(MHD)electroosmotic flow(EOF)of Newtonian fluid through a zeta potential modulated parallel plate microchannel with patterned hydrodynamic slippage.The driven mechanism of the flow originates from the Lorentz force generated by the interaction of externally imposed lateral electric field E_y and vertical magnetic field B_z and electric field force produced by an externally applied electric field E_x.It is assumed that the wall zeta potential and the slip length are periodic functions of axial coordinate x,an analytical solution of the stream function is achieved by utilizing the method of separation of variables and perturbation expansion.The pictures of streamlines are plotted and the vortex configurations produced in flow field due to patterned wall potential and hydrodynamic slippage are discussed.Based on the stream function,velocity field and volume flow rate are obtained,which are greatly depend on some dimensionless parameters,such as slip length l_s,electrokinetic width ?,the amplitude ? of the patterned slip length,the amplitude m of the modulated zeta potential and Hartmann number Ha.The variations of velocity and volume flow rate with these dimensionless parameters are discussed in details.These theoretical results may provide some guidance effectively operating micropump in practical nanofluidic applications.