BENDING OF MEMBRANES BY ANCHORED POLYMERS

Polymers which are attached to a fluid membrane by a single anchor exhibit a dilute mushroom regime and a semi-dilute brush regime. Sealing arguments and explicit calculations for ideal polymers show that the membrane is bent by the anchored polymer: For smooth bends, an anchored mushroom with linear size R(po) induces a spontaneous curvature of order similar or equal to T/kappa R(po), where T and kappa are the temperature and the bending rigidity, respectively; for sharp cone-like bends, it induces a bending angle similar to T/2 pi kappa. A brush, with mean anchor separation xi(an) leads to a curvature of order similar or equal to (R(po)/xi(an))T-2/nu/kappa xi(an).