Statistical mechanics of membrane adhesion by reversible molecular bonds

We present a simple statistical-mechanical model for membranes adhering by thermally fluctuating, reversible molecular bonds. The free energy of the molecular bonds, which interact through the membrane tension, can be related to that of the one-component two-dimensional Coulomb plasma in the grand-canonical ensemble. Using the known properties of the Coulomb plasma, we compute the macroscopic membrane-membrane adhesive potential. We find that, unlike existing theories of membrane adhesion, thermal fluctuations assist adhesion and that the weak-adhesion potential has an unexpectedly long, temperature-controlled range.