  The piezoresistive response of granular metals under uniaxial strain is
strongly dependent on the concentration of the conducting phase. Here we show
that the piezoresistive anisotropy is reduced as the system approaches its
percolation thresold, following a power law behavior in the critical region. We
propose a simple relation between the conductance and the piezoresistive
anisotropy which could be used in relation to real materials and notably to the
thick film resistors.
