FLUCTUATION-MAGNIFICATION OF NONEQUILIBRIUM MEMBRANES NEAR A WALL

Membranes in thermal equilibrium are well known to exhibit Brownian mo tion type shape fluctuations. Membranes containing active force center s - such as chemically active membrane proteins suffer additional non- equilibrium shape fluctuations due to the activity of these force cent ers. We demonstrate, using scaling arguments, that non-equilibrium sha pe fluctuations are in general greatly amplified by the presence of a nearby wall or membrane due to the absence of a fluctuation-dissipatio n theorem. For adhesive membranes, this fluctuation magnification effe ct may facilitate the establishment of bonding. For non-adhesive membr anes, fluctuation magnification produces a long-range repulsive pressu re which can exceed the well known Helfrich repulsion due to purely th ermal fluctuations.