Tomographic-like reconstruction of the percolation cluster as a phase   transition
  We observed a phase transition-like behavior that is marked by the onset of the realization of the connectivity between two sites on a two-dimensional cross-section of a three-dimensional percolation cluster. This was found using contact-resistance atomic force microscopy on carbon black/polymer composites. The features in the current images, when presented as a function of the cut-off current, or as a function of the total area covered by the electrically connected objects, appear to obey a cluster statistics that is similar to the one predicted and observed in continuum percolation systems. 
Nira Shimoni, Doron Azulai, Isaac Balberg and Oded Millo