Numerical investigation of electroosmotic-driven cilia-induced peristaltic flow of non-Newtonian Johnson–Segalman nanofluids with gyrotactic microorganisms

Purpose – This study aims to develop a comprehensive model for electroosmotically driven peristaltic transport of a non-Newtonian Johnson–Segalman fluid in a vertically oriented, ciliated microchannel with symmetric geometry. This study seeks to examine the combined influence of nanoparticle dispersion, shear-responsive microorganism motility and electroosmotic forces on fluid transport behavior relevant to advanced microfluidic systems. Design/methodology/approach – A mathematical model is formulated incorporating key physical parameters, including thermophoresis, Brownian motion, electric conductivity, Helmholtz–Smoluchowski velocity, viscosity, relaxation time and thermal conductivity. The governing coupled nonlinear differential equations are solved numerically using the finite element method under appropriate boundary conditions to analyze flow characteristics, particle distribution and microorganism dynamics. Findings – The results of this study reveal that stronger electroosmotic effects significantly enhance volumetric flow rates. Increased ciliary activity and higher nanoparticle concentrations reduce flow trapping and improve particle dispersion uniformity. Additionally, channel symmetry plays a crucial role in shaping streamline patterns and enhancing microorganism transport efficiency. Originality/value – This study proposes a previously unexplored coupling of electroosmotic peristaltic cilia flow with non-Newtonian Johnson–Segalman fluid, incorporating nanoparticles and motile microorganisms in a symmetric configuration.