2018/01/20 by Kumari Priti Sinha, Rochish Thaokar, Rochish M Thaokar · 11 citations
Engineering · Medicine · Physics and Astronomy · #Blood properties and coagulation #Composite material #Deformation (meteorology) #Electric field #Electrohydrodynamics and Fluid Dynamics #Materials science #Mechanics #Microfluidic and Bio-sensing Technologies #Physics #Shear (geology) #Shear flow #Shear stress #Simple shear #cond-mat.soft
paper · pdf · doi:10.1103/physreve.97.032404
published in Physical review. E 97(3), 032404 (American Physical Society)
arxiv created 2018/01/20 · openalex publication_date 2018/03/12 · arxiv updated 2018/03/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Vesicles or biological cells under simultaneous shear and electric field can be encountered in dielectrophoretic devices or designs used for continuous flow electrofusion or electroporation. In this work, the dynamics of a vesicle subjected to simultaneous shear and uniform alternating current (ac) electric field is investigated in the small deformation limit. The coupled equations for vesicle orientation and shape evolution are derived theoretically, and the resulting nonlinear equations are handled numerically to generate relevant phase diagrams that demonstrate the effect of electrical parameters on the different dynamical regimes such as tank treading (TT), vacillating breathing (VB) [called trembling (TR) in this work], and tumbling (TU). It is found that while the electric Mason number (Mn), which represents the relative strength of the electrical forces to the shear forces, promotes the TT regime, the response itself is found to be sensitive to the applied frequency as well as the conductivity ratio. While higher outer conductivity promotes orientation along the flow axis, orientation along the electric field is favored when the inner conductivity is higher. Similarly a switch of orientation from the direction of the electric field to the direction of flow is possible by a mere change of frequency when the outer conductivity is higher. Interestingly, in some cases, a coupling between electric field-induced deformation and shear can result in the system admitting an intermediate TU regime while attaining the TT regime at high Mn. The results could enable designing better dielectrophoretic devices wherein the residence time as well as the dynamical states of the vesicular suspension can be controlled as per the application.