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DY: Fachverband Dynamik und Statistische Physik

DY 54: Posters - Pattern Formation, Reaction Diffusion, Chimera

DY 54.9: Poster

Donnerstag, 23. März 2017, 17:00–19:30, P1A

Membrane Instability Driven by an AC Electric Field — •Mirko Ruppert¹, Walter Zimmermann¹, and Falko Ziebert^1,2 — ¹Theoretische Physik, Universität Bayreuth, Bayreuth, Germany — ²Physikalisches Institut, Universität Freiburg, Freiburg, Germany

Unilamellar vesicles are important model systems in biophysics. They are typically created by applying a voltage on a stack of flat membrane bilayers, but this so-called electroformation process is still poorly understood. Models exist for the case of a static (dc) electric field, but experimentally typically ac fields of about 10 Hz have to be used. We therefore study the ac field-induced instability of a flat capacitive membrane with respect to spatial modulations, using an effective zero-thickness model developed previously in the dc case. The instability of the membrane is driven by the charge accumulation in the Debye layers and the voltage drop at the membrane. Increasing the driving frequency or reducing the amount of salt reduces the instability. By a full Floquet analysis of the linear, coupled Poisson-Nernst-Planck-Stokes boundary value problem we found that the instability is with respect to finite wavenumber undulations, in contrast to the static case where the instability is long-wavelength.