Equilibrium electrodeformation of a spheroidal vesicle in an ac electric field
Equilibrium electrodeformation of a spheroidal vesicle in an ac electric field
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DOI：
10.1103/physreve.88.052718
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发表时间：
2013-11-25
影响因子：
2.4
通讯作者：
Young, Y. -N.
中科院分区：
文献类型：
--
作者：
Nganguia, H.;Young, Y. -N.
在这项工作中，我们开发了一个理论模型来解释巨型单层囊泡（GUV）在交变（ac）电场下的平衡球体变形。囊泡膜悬浮在泄漏的介电流体中，被建模为薄电容球壳。平衡囊泡形状是由粘性流体的机械力、恢复弹性膜力和外部施加的电力之间的平衡产生的。我们的球体模型预测了变形依赖性跨膜电位，并且能够捕获囊泡在电场下的大变形。与实验和小变形（准球形）理论的详细比较表明，球体模型在对流体电导率、介电常数比、囊泡尺寸、电场强度和频率的依赖性方面与实验具有更好的一致性。球体模型还允许对平衡囊泡形状在长长形和扁圆形之间交叉的交叉频率进行渐近分析。比较表明，球体模型与实验观察结果更加吻合。
In this work, we develop a theoretical model to explain the equilibrium spheroidal deformation of a giant unilamellar vesicle (GUV) under an alternating (ac) electric field. Suspended in a leaky dielectric fluid, the vesicle membrane is modeled as a thin capacitive spheroidal shell. The equilibrium vesicle shape results from the balance between mechanical forces from the viscous fluid, the restoring elastic membrane forces, and the externally imposed electric forces. Our spheroidal model predicts a deformation-dependent transmembrane potential, and is able to capture large deformation of a vesicle under an electric field. A detailed comparison against both experiments and small-deformation (quasispherical) theory showed that the spheroidal model gives better agreement with experiments in terms of the dependence on fluid conductivity ratio, permittivity ratio, vesicle size, electric field strength, and frequency. The spheroidal model also allows for an asymptotic analysis on the crossover frequency where the equilibrium vesicle shape crosses over between prolate and oblate shapes. Comparisons show that the spheroidal model gives better agreement with experimental observations.