Lipid bilayers and thermal fluctuations

Lipid bilayers are increasingly used as ideal models of cell membranes. They are characterised by their static structure and dynamic thermal fluctuations.

Fluctuations may strongly influence different self-assembly properties of lipid membranes and their interaction with biological molecules such as proteins. Samples of stacks of lipid bilayers in a highly hydrated environment are ordered in one dimension giving rise to Bragg diffraction peaks.

The figure shows the off-specular scattering in 2θ stemming from thermal fluctuations. The analysis of the specular and off-specular pattern allowed the determination of the bilayer structure and fluctuations covering length scales from sub-nanometer up to a few hundred nanometers.

Ref.: T. Salditt, et al., Langmuir (2003) 19, 7703.