ELECTRIC-FIELD-DEPENDENT THERMAL FLUCTUATIONS OF GIANT VESICLES

The influence of an ac electric field on the shape and thermal fluctua tions of giant vesicles is theoretically investigated. The experiments show that at high frequencies (dielectric regime) vesicles deform int o oblate ellipsoids with the symmetry axis parallel to the applied ele ctric field, while at low frequencies (conductive regime) they deform into prolate ones. Depending on the medium conductivity, the transitio n frequency between both regimes may be as low as a few kilohertz.