Semiflexible Polymers and Filaments: From Variational Problems to Fluctuations

Abstract

We discuss shapes and shape fluctuations of semiflexible polymers or filaments, which are polymers with an appreciable bending rigidity. The physical properties of semiflexible polymers are governed by their persistence length. On length scales smaller than the persistence length thermal fluctuations can be neglected and polymer shapes are obtained by bending energy minimization. On length scales larger than the persistence length, however, thermal shape fluctuations play an important role and cannot be neglected in general. After a general definition of the persistence length based on the bending rigidity renormalization we will review some problems related to single semiflexible polymers where both variational problems of energy minimization and thermal fluctuations play an important role. We will discuss the buckling instability of semiflexible polymers, their force‐induced desorption, and the shapes of adsorbed semiflexible polymers on structured substrates.