Contents
1      Introduction	2
2      Surface Charge Density, Surface and Zeta Potentials	4
3      pH Effects	5
4      Effects of Ions Different from Protons	6
4.1      Metal Cations	6
4.2      Cationic Peptides	9
5      Potentials across Membranes	11
5.1      Electromechanical Coupling	11
5.2      External Electric Fields and Electroporation	13
5.3      Nerve Impulse Propagation	15
6      Summary and Future Perspectives	17
References	18