Figure 20.

Theory of pore formation in membranes by electric fields. (A) Schematic of pore formation showing the transition from a hydrophobic pore to a hydrophilic (conducting) pore. (B) Graphs of relationship between free energy of pores ΔW and pore radius r for ΔΦ _m = 0 (upper curve) and at ΔΦ _m > 0 (lower curve). r_* is the critical radius corresponding to the transition from hydrophobic to hydrophilic pore. ΔW_f corresponds to the height of the energy barrier for pore formation while ΔW_res relates to the energy barrier height for pore resealing. r_ire is the pore radius corresponding to state of irreversible electroporation. ΔΦ _m is the electrical potential difference across the membrane. Panel A and B reproduced from reference 239²³⁹. (C) Calculations of the effect of applied voltage on the energy landscape of pore formation with transmembrane potentials ranging from 0 to 0.5 V. Panel C reproduced from reference 389³⁸⁹.