Mechanical properties of ZnO nanowires

Abstract

One-dimensional solids like nanowires and nanotubes are potential materials for future nanoscale sensors and actuators. Due to their unique length scale, they exhibit superior mechanical properties and other length scale dependent phenomena. In this paper, we report experimental investigations on the mechanical properties of ZnO nanowires. We have designed a MEMS test-bed for mechanical characterization of nanowires. The MEMS device exploits the mechanics of post-buckling deformation of slender columns to achieve very high force and displacement resolution. The small size of the test-bed allows for in situ experimentation inside analytical chambers, such as SEM and TEM. We present microscale version of pick-and-place as a generic specimen preparation and manipulation technique for experimentation on individual nanostructures. We performed experiments on ZnO nanowires inside a scanning electron microscope (SEM) and estimated the Young's modulus to be about 21 GPa and the fracture strain to vary from 5% to 15%.