[Electrostriction of plane lipid membranes and elasticity moduli]

A comparative analysis is given of the data on measuring the deformation of bilayer lipid membranes (BLM) by the optical (reflexometry) and capacity methods with regard to both the electrostatic forces compressing the bilayer and the changes in bilayer tension. The essential difficulties in interpreting (in terms of elastic modulus) the data on electrostriction changes in BLM integral capacity are shown. Based on the optical data it is shown that most "soft" BLM formed from lipid solution in short-chain (below n-decane) alkanes have a cross-section elasticity modulus E no less than 10(-7) Pa even at zero frequency. The elasticity modulus in the membrane plane upon isotropic tension (E) is about two times as much as E. At a voltage jump, the time of establishing a new value of the contact angle theta between the volumic phase (torus) and the bilayer and, respectively, of a new value of bilayer tension does not exceed 0.25 ms.