PERCOLATION IN 2-DIMENSIONAL CONDUCTOR-INSULATOR NETWORKS WITH CONTROLLABLE ANISOTROPY

The conductivities of two-dimensional conductor-insulator networks generated photolithographically from laser speckle patterns have been measured. Isotropic networks with 450 000 statistically independent units show a percolation threshold fc 41% conductor and a critical exponent t 1.30. Measurements on anisotropic networks and numerical simulations indicate that either fc, t, or the size of the asymptotic region" must vary with the degree of anisotropy. © 1979 The American Physical Society."