Fig. 3

Theoretical model. Schematic representation of the FM-DEP force exerted on a cell that is modelled as a homogeneous sphere model having the permittivity and conductivity of ε_in and σ_in, respectively. The sphere is surrounded by electrolyte medium with its permittivity and conductivity of ε_out and σ_out, respectively. The homogeneous sphere model is the simplification of the spherical single shell model that regards the cell as a smeared-out cytoplasm surrounded by a membrane [9]