Berlin 2005 – wissenschaftliches Programm
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AKB: Biologische Physik
AKB 200: Poster Session II
AKB 200.2: Poster
Dienstag, 8. März 2005, 17:00–19:00, Poster TU C
Geometry of interface mediated interactions — •Martin Michael Müller1, Markus Deserno1, and Jemal Guven2 — 1Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany — 2Instituto de Ciencias Nucleares, UNAM, Apdo. Postal 70-543, 04510 México D.F., Mexico
Soft interfaces can mediate interactions between particles bound to them. One example is the interaction of protein inclusions in a lipid membrane. Traditionally, this phenomenon is treated by calculating the total energy of the particle-interface-system as a function of particle positions. The forces between the bound particles can then be obtained via appropriate derivatives. Unfortunately, the intrinsic nonlinearity of the problem generally forces one to restrict to linear approximations of the energetics.
It is, however, possible to choose a different, covariant approach and gain some nonlinear results: The forces between the particles are mediated through the interface and are thus encoded in its geometry. In analogy to classical elasticity theory one can write them as integrals over the surface stress tensor, which itself depends in a transparent way on the interfacial energy density. For standard symmetric two-particle situations this approach yields exact formulas for the force in terms of the mid-plane geometry, the sign of which is sometimes evident.