A linear piezoelectric actuator using the first-order bending modes

A linear piezoelectric actuator using the first-order bending modes is proposed, designed, fabricated and tested in this study. The proposed actuator contains two exponential shape horns located on the two leading ends. Two groups of PZT elements are clamped between the two horns by a bolt to excite two first-order bending modes of the actuator. These two bending vibrations are orthogonal in space, which can produce elliptical movements on the hornsʹ tip ends when they have the same resonance frequency and a phase shift in time of π/2. The structure and working principle of the proposed actuator are introduced. The input impedance characteristics of the proposed actuator are calculated and discussed. After the fabrication of a prototype, its vibration modes are tested using a scanning laser Doppler vibrometer. Finally, the mechanical ability of the prototype is tested. This study verifies that the bending mode with lower order can help a lot in improving the power density.