Anomalous diffusion on crumpled wires in two dimensions

The statistical properties of random walks evolving on real configurations of a crumpled wire rigidly jammed in two dimensions is investigated. These crumpled hierarchical structures with complex topology are obtained from a metallic wire injected at a constant rate into a transparent planar cell of 20 cm of diameter. The observed diffusion is anomalous with an exponent very close to that obtained at the threshold of two dimensional percolation. A comparison of the system studied in this paper with other systems of physical interest is also made, and an experimental consequence of our results is discussed.