= Electro-osmosis
{wiki}
= Electroosmotic flow
{synonym}
= Electroosmosis
{synonym}
Electro-osmosis is fluid motion driven by an applied <electric field> acting on mobile <electric charge> near a surface. A charged interface attracts a diffuse population of <counterions> in an <electric double layer>. A field component tangent to the interface exerts a force density $\rho_e\mathbf E$ on that mobile charge; momentum transfer to the surrounding <solvent> drives flow opposed by <viscous stress>. In a capillary <electrophoresis> measurement, this flow advects the sample as well as its electrical drift relative to the fluid. Locally, the measured axial <velocity> is $v_{\mathrm{observed}}=u_{\mathrm{eo}}+\mu_{\mathrm{ep}}E$, where $u_{\mathrm{eo}}$ is the electroosmotic fluid velocity and $\mu_{\mathrm{ep}}$ is the <electrophoretic mobility>. https://ocw.mit.edu/courses/6-777j-design-and-fabrication-of-microelectromechanical-devices-spring-2007/ecbd3da50020e79e0cbb85a43a9604c1_07lecture15.pdf[MIT OpenCourseWare, lecture 15: electroosmotic flow driven by the force on diffuse-double-layer charge]{ref}
Back to article page
