Solving EDL configuration near a dissimilarly charged protrusions surface model using perturbation method

In this work, an elementary, novel dissimilarly charged protrusions (DCP) surface model in an electrolyte solution considering simultaneously the complexity of both surface morphology and surface charged condition, which are concerned frequently on a biological cell membrane, on a modified micro-particle surface, or in a lab-on-a-chip biosensor device, is proposed. Based on Fourier series and the perturbation technique, the configuration of electrical double layer (EDL) near this complicated charged surface model is successfully solved semi-analytically. The numerical calculation reveals that, the methodology suggested in present study could deal with charged surface systems of arbitrary geography and of arbitrary charge distribution. In the analysis, three special subjects are discussed, including an isolated dissimilarly charged protrusion, the effect of protrusions, and the effect of dissimilarly charged condition on protrusions.