Giant piezoresistance in silicon/metal hybrid resistors

We report a giant room temperature piezoresistance in planar metal/semiconductor hybrid resistors fabricated from Aluminum and Silicon, with gauge factors $\sim $1000 for strains up to 10$^{-5}$. This new effect [1] is shown to be due to the geometric arrangement of the metal and the semiconductor, and results from a stress induced redirection of the injected current from the metallic shunt into the semiconductor. Since there is a large difference in the electrical conductivity of these materials, this yields a large increase in the device resistance. This ``extraordinary piezoconductance'' will be compared and contrasted with the extraordinary magnetoresistance previously observed in metal/semiconductor hybrid resistors. \\[4pt] [1] A.C.H. Rowe et al., Phys. Rev. Lett. 100, 145501 (2008)