Study on the coupling effect of a plate-type piezoelectric vibrator and a polymer-based rod array

In this paper, we present our study on using a plate-type piezoelectric vibrator to excite vibrations of a vero polymer-based rod array efficiently. The plate-type piezoelectric vibrator consists of a 0.13 mm thick stainless steel plate and a 0.2 mm thick PZT plate. The stainless-steel and PZT plates were designed to be an unimorph structure in which bending vibrations can easily be excited. As the vero rod array is made of a polymer, its stiffness will be much lower than that of the PZT actuator. As a result, the Vero rod array can be considered an external loading unit and equivalently incorporated into a vero layer base plate. By designing the electrode positions of the PZT layer in the plate-type vibrator, the vero rod array can be excited effectively and generate large displacement in the Z direction. These designs can compensate for the stiffness difference between the piezoelectric vibrator and the vero polymer-based rod array. According to finite element analysis, the transient maximum displacement at the top of the rod can reach 79 μm, while the steady state displacement is 50 μm in the out-of-plane Z direction at the mode 21 resonance frequency. At the mode 31 resonance frequency, the transient maximum displacement at the top can reach 28 μm, while the steady state displacement is 18 μm in the Z direction. This result demonstrates that by incorporating driving frequencies and bending modes of the piezoelectric vibrator, mechanical vibrations can be coupled to the polymer rod array.