(Color online) Toy model of ion channel. (a) Potential map inside the cylindrical channel at z = 0 due to dipole rings embedded in the membrane. (b) Potential map at the same coordinate when 3 adjacent dipoles are switched off in each ring. The potential is the sum of both source charge and induced charge Coulombic contributions.
Berti et al. Nanoscale Research Letters 2012 7:135 doi:10.1186/1556-276X-7-135