||Evan. Evans, David. Needham, Physical properties of surfactant bilayer membranes: thermal transitions, elasticity, rigidity, cohesion and colloidal interactions. J. Phys. Chem., 1987, 91 (16), pp 4219–4228 DOI: 10.1021/j100300a003 link p.4219 left column top paragraph
||p.4219 left column top paragraph: "The lamellar configuration of biological membrane structures is peculiar to the preferential assembly of amphiphilic molecules into molecular double layers. The strong preference for the lamellar configuration is evidenced by the negligible solubility of these molecules-and extremely slow rate of exchange from a membrane capsule-in aqueous media. In this condensed state, bilayer membranes exhibit solid- or liquidlike material behavior with the common feature of limited surface compressibility (i.e. great resistance to change in surface density). Because of the thin structure (~(3-4)×10^-7cm), bilayer fragility and limited detectability by optical methods create significant obstacles to measurement of the physical-mechanical properties. Recently, micromechanical techniques have been developed to investigate thermal transitions, cohesion, elasticity, and surface rigidity of bilayer membranes in situ [refs 1-3]."