Relaxation and flow in linearly sheared two-dimensional foams
  We probe the relation between shear induced structural relaxation and rheology in experiments on sheared two-dimensional foams. The relaxation time, which marks the crossover to diffusive bubble motion, is found to scale non-trivially with the local strain rate. The rheology of the foam is shown to be intimately linked to the scaling of the relaxation time, thus connecting macroscopic flow and microscopic bubble motion. 
Matthias E. M\"obius, Gijs Katgert and Martin van Hecke