Figure 4.

A model illustrating the potential (Φ) across the cell membrane. The intra- and the extracellular media are separated by the lipid bilayer (region c) having the thickness δ_bi, the permittivity ε_bi, the inner intrinsic surface membrane charge σ_i, and the outer intrinsic surface membrane charge σ_o. The inner (region b) and the outer (region d) Stern layers that reside next to the membrane have the thickness ${\mathit{\delta }}_{\mathit{i}/\mathit{o}}^{\mathit{s}}$ and the permittivity ${\mathit{\epsilon }}_{\mathit{i}/\mathit{o}}^{\mathit{s}}$ (i and o represent inner and outer). The inner (region a) and outer (region e) diffuse layers are located next to the Stern layer. To see this figure in color, go online.