Study on bandgap properties of a piezoelectric phononic crystal nanobeam with surface effects
The model of piezoelectric phononic crystal nanobeam is proposed by periodically repeating elastic ma-terial epoxy and piezoelectric material PZT-4 at nanoscale along the axial direction.The plane wave expansion method with surface effects is derived and formulized by coupling surface piezoelectric theory,Euler beam theory and traditional plane wave expansion method to calculate the corresponding band structures.Moreover,the exter-nal electrical voltage and axial force are chosen to investigate the influences of electro-mechanical coupling effects on band gaps.Residual surface stress and material intrinsic length are picked as the influencing parameters relat-ed to surface effects.Ratio of the length of PZT-4 to that of epoxy in a unit cell and the height-width ratio are chosen to research the effects of geometric parameters on band gaps.The results and analysis are expected to be helpful in designing piezoelectric nanobeam-based devices.