New design of piezoelectric plate-type vibrator based on quasi-traveling wave

Abstract

This paper proposes a novel piezoelectric vibrator using a two-layer rectangular plate with the sizes of 90 × 50 × 20 mm3, to produce quasi-traveling wave in a compact structure. The excited quasi-traveling waves propagate along the surface of a rectangular plate, depending on the superposition of two orthogonal flexural vibration modes with a spatial phase difference of 90°. Piezoelectric ceramic patches are used to excite two working modes of the vibrator. In the study, we first design a mass-block type vibrator (M-type) and a tail type vibrator (T-type), and demonstrate the excitation of quasi-traveling wave on the plate. Second, we design the piezoelectric vibrator and use finite element method (FEM) to perform eigen-frequency degeneration. After that, the designed vibrators, consisting of a two-layer aluminum plate structure with blocks at both ends and eight piezoelectric patches bonded on back surface of the plate, are manufactured and tested. Then experimental characterization of two types of vibrators is carried out, and results are revealed. The excitation and propagation of quasi-traveling wave are also proved by laser vibration test. Our experimental results show that maximum driving amplitude of this piezoelectric plate-type vibrator is 10 μm, the excitation frequency is about 3–18 kHz, and voltage is 50–80 Vpp.