"Dynamics in Steady State in-Vitro Acto-Myosin Networks"

We show that complex fluids such as actin networks respond to deformations differently at intermediate length scales than they do as a bulk material, at large distances. When characterizing passive entangled F-actin networks we found that this intermediate response regime, characterized by an r^-3 decay with distance, persists to surprisingly large distances of 2-6 µm, which is comparable the size of a cell, and over ten times larger than the mesh size of the actin network. A similar cross-over was observed previously in microtubule networks at r_c=15µm, if not as clearly, and without explanation. We use this newfound understanding to extract structural information of active in-vitro reconstituted cytoskeleton networks, in which such analysis can be done in a controlled fashion