Micro mechanical single crystal silicon fracture studies torsion and bending

We introduce a micro electro mechanical system to characterize materials as their size is reduced to submicron scale. We employ the system to study the strength of a single crystal silicon pillar subjected to twisting and bending. The minimum width of the pillar is 0.5 /spl mu/m. Its length is less than 10 /spl mu/m. It twists by more than 20/spl deg/ before failure. The maximum normal and shear stress at failure are estimated to be 20 GPa and 8.5 GPa respectively.