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Elastic Properties of Lipid Bilayers: Theory and Possible Experiments
  • W. Helfrich
  • Chemistry, Materials Science
  • Zeitschrift fur Naturforschung. Teil C: Biochemie…
  • 1 December 1973
Abstract A theory of the elasticity of lipid bilayers is proposed. Three types of strain, i. e. stretching, tilt and curvature, are distinguished and the associated stresses are identified. It isExpand
Steric Interaction of Fluid Membranes in Multilayer Systems
Abstract The out-of-plane fluctuations of fluid membranes are sterically hindered in multilayer systems. The repulsive interaction associated with the steric or excluded-volume effect is studiedExpand
Undulations, steric interaction and cohesion of fluid membranes
SummaryThe theory of undulations of fluid membranes is reviewed and in some parts extended. The functional dependences of the steric interaction of undulating membranes are derived in a new way fromExpand
The curvature elasticity of fluid membranes : A catalogue of vesicle shapes
2014 Shapes of closed fluid membranes such as those formed by lecithin in water were calculated as a function of enclosed volume, membrane area and spontaneous curvature. As the area can be taken toExpand
Voltage-Dependent Optical Activity of a Twisted Nematic Liquid Crystal
A new electro‐optical effect in twisted nematic liquid crystals is described which allows variation of the rotation of linearly polarized light continuously from 0° to 90°. It requires lower voltagesExpand
Effect of thermal undulations on the rigidity of fluid membranes and interfaces
Thermal undulations of fluid layers, whose strength depends on layer rigidity, are shown to reduce the effective rigidity. The decrease is calculated in a first-order approximation for weak rippling.Expand
The Bending Rigidity of Phosphatidylcholine Bilayers: Dependences on Experimental Method, Sample Cell Sealing and Temperature
The bilayer bending rigidities were measured for the same spherical vesicles with two methods, fluctuation mode analysis and electric deformation. In some of the sample cells the glue sealing theExpand
Deformation of spherical vesicles by electric fields
Abstract We calculate the strength of the ellipsoidal deformation of spherical vesicles in water by AC and DC electric fields.
Steric Interaction of Fluid Membranes
Optical observation of giant lecithin vesicles does not show any indication of cohesion between thin lecithin membranes consisting of a small number of bilayers (W. Harbich, H. J. Deuling, and W.Expand
Osmotic shrinkage of giant egg-lecithin vesicles.
Osmotic shrinkage of giant egg-lecithin vesicles was observed by phase-contrast microscopy. The vesicles remained or became spherical when shrinking. Small and thick-walled vesicles formed visibleExpand