Surface effects on the post-buckling of piezoelectric nanowires

Due to the large ratio of surface to volume, surface effects play an essential role in determining the physical properties of nanoscaled structures. A theoretical model is developed in this work to investigate the effect of surface on the postbuckling behavior of piezoelectric nanowires, in which the residual surface stresses, surface piezoelectricity and surface elasticity are taken into consideration. The critical buckling strain and the amplitude of the buckled nanowire are analytically obtained. It is found that the critical buckling strain ratio increase with the decrease of the thickness of piezoelectric nanowire, which demonstrates that the surface becomes prominent when the thickness of piezoelectric nanowire is at nano-scale. The theoretical estimation agrees well with the experimental data on a single crystal ZnO nanowire. This study provided the fundamental understanding of the physical behavior of piezoelectric nanowires and is promising for designing piezoelectric nanowire based stretchable nanoelectronics.