Propagation of a thermo-mechanical perturbation on a lipid membrane.

The propagation of sound waves on lipid monolayers supported on water has been previously studied during the melting transition. Since changes in volume, area, and compressibility in lipid membranes have biological relevance, the observed sound propagation is of paramount importance. However, it is unknown what would occur on a lipid bilayer, which is a more approximate model of a cell membrane. With the aim to answer this relevant question, we built an experimental setup to assemble long artificial lipid membranes. We found that if these membranes are heated in order to force local melting, a thermo-mechanical perturbation propagates a long distance. Our findings may support the existence of solitary waves, postulated to explain the propagation of isentropic signals together with the action potential in neurons.