Articles techniques et présentations

Ion-selective membranes can be used in lab-on-a-chip devices for various portable applications in this field. These devices can be used as concentrators for analytical chemistry and for micro-scale filtration.

Here, a binary aqueous electrolyte solution in a microchannel has a potential bias applied across it and it is driven through an ion-selective membrane. Ion concentration gradients form on each side of the membrane. Asymmetry in these diffusion layers induces an electric current rectification effect.

We investigate theoretically how 2D flux and field focusing effects contribute to diffusion layer asymmetry in comparison to 1D models with different diffusion layer length scales. A region of fixed charge density acts as the ion-selective membrane.