Influence of Surface Texture on the Variation of Electrokinetic Streaming Potentials

The electrokinetic streaming potential (V-s) obtained through electrolyte flow in a microchannel is shown to be related to the underlying surface pattern. Pillar, mesh, and groove patterns were studied for comparing the relative magnitudes of the V-s with air-/liquid-filled surfaces. A record value of the related figure of merit, in terms of the developed V-s per-unit applied pressure, of similar to 0.127 mV/Pa, was observed in a mesh texture liquid-filled surface (LFS) impregnated with an electrolyte-immiscible oil. The study indicated that increasing the solid fraction of the pattern surface decreases the effective slip length while enhancing the overall channel zeta potential. Consequently, maximizing the obtained V-s implies a balancing of the slip with the surface potential, with plausibly more significance of the latter. The work has implications for higher-efficiency electrical voltage sources.

Automated summary

The study shows that the electrokinetic streaming potential in a microchannel is related to the underlying surface pattern, with different patterns affecting the magnitude of the potential. By increasing the solid fraction of the pattern surface, the effective slip length decreases while enhancing the overall channel zeta potential, ultimately impacting the efficiency of electrical voltage sources.