Change in the Electric Current Required to Sustain Steady Electroosmotic Flow in a Capillary

Abstract

For electroosmotic flow (EOF) in a capillary, a method is established to locate the frontal zone between the injected and ejected solutions, based on the change in the electric current required to sustain the EOF when there is a difference of electric conductivity between the injected and ejected solutions. When a certain voltage is applied between the two ends of a capillary filled with a solution, the EOF is generated in the capillary, the flow profile of which is flat, in contrast to that of the Poiseuille flow. Although the EOF moves the frontal zone with constant velocity, the monitored electric current required to sustain the EOF under a constant voltage is found to change according to a hyperbolic function of time. By associating the injected and ejected solutions with two resistances connected in series, an accurate account is given of the change in the electric current while the frontal zone progresses through the capillary.

Microstructure formation on titanium oxide (TiO₂) coatings by femtosecond laser irradiation

“…4) The purpose of this study is to improve the chemical functions of the surfaces of solids that are in contact with a liquid through femtosecond laser micromachining. 5) Therefore, we have carried out fundamental experiments on the micromachining of titanium oxide coatings using a femtosecond laser.…”