Electrodeformation method for measuring the capacitance of bilayer membranes

Abstract

We report a novel non-invasive method to measure the capacitance of biomimetic bilayer membranes. The approach utilizes the frequency-dependent deformation of giant unilamellar vesicles in AC uniform electric field. The method is applied to membranes made of lipids and polymers. Compared to lipid membranes, polymer bilayers have an order of magnitude lower capacitance, which correlates with their larger thickness. The capacitance of both lipid and polymer bilayers is found to be voltage-independent in the examined range between 2 and 6 kV m⁻¹, indicating membranes do not experience significant thinning due to electrostriction.