Response of actin networks at intermediate distances


  Adar Sonn-Segev [1]  ,  Anne Bernheim-Groswasser [2]  ,  Haim Diamant [1]  ,  Yael Roichman [1]  
[1] School of Chemistry, Tel Aviv University
[2] Department of Chemical Engineering, Ben Gurion University of the Negev

We report the observation of a large-distance intermediate response in an experimental system of entangled F-actin gels. The tools of 1-point and 2-point microrheology were used to characterize the local and distance-dependent responses of the actin networks, respectively. The 2-point response at intermediate distances, arising from the effect of mass displacement rather than momentum diffusion, is enhanced by the much softer local microenvironment of the tracers compared to the bulk properties of the gel. Consequently, the intermediate behavior sets in at particle separations much larger than the mesh size, ξ, of the actin gel. Results from several networks with different mesh sizes will be presented, emphasizing this inherent property of complex fluids and its relation to ξ.