Electrical Bragg Band Gaps In Piezoelectric Plates With A Periodic Array Of Electrodes

This paper concerns a piezoelectric bar or plate, poled along its thickness, that supports on its top and bottom surfaces a periodic grating of electrodes. An analytical model is developed considering wave propagation along the length of the plate/bar. It shows that an electrical Bragg band gap can be observed, depending on the electrical boundary conditions applied on the electrodes. This gap is associated with a discontinuity of the electric field between two successive unit cells. The model is validated with the finite element method. The paper shows that the electrical Bragg band gap is highly tunable and can be optimized by changing the orientation of the material.