Viscoelasticity of isotropically cross-linked actin networks.

Despite their importance for the proper function of living cells, the physical properties of cross-linked actin networks remain poorly understood as the occurrence of heterogeneities hamper a quantitative physical description. The isotropic homogeneously cross-linked actin network presented here enables us to quantitatively relate the network response to a single filament model by determining the dominating length scale. The frequency dependence of the linear response and nonuniversal form of the nonlinear response reveal the importance of cross-linker unbinding events.