Longitudinal and transverse piezoresistive response of granular metals -: art. no. 064201

We study the piezoresistive response and its anisotropy for a bond-percolation model of granular metals. Both effective-medium results and numerical Monte Carlo calculations of finite simple-cubic networks show that the piezoresistive anisotropy is a strongly dependent function of bond probability p and of bond conductance distribution width Deltag. We find that piezoresistive anisotropy is strongly suppressed as p is reduced and/or Deltag is enhanced and that it vanishes at the percolation threshold p = p(c). We argue that a measurement of the piezoresistive anisotropy could be a sensitive tool to estimate critical metallic concentrations in real granular metals.