Electrode design of multilayered piezoelectric transducers for longitudinal-bending ultrasonic actuators

Abstract

To improve the controllability of ultrasonic linear motors in the longitudinal-bending mode, we have developed a multilayered transducer with independent electrode sets for the first longitudinal mode and the second bending mode. Since the vibration components are controlled independently by the transducer, it is possible to change only the driving vibration component with the component for friction control kept constant. The optimal shape and area of the electrodes in terms of efficiency were investigated analytically and experimentally. It was confirmed that an electrode shape in accordance with the mode strain contour gave a large output and that an optimum electrode area existed. The transducer with an optimal electrode pattern exhibited an efficiency improvement of approximately 10% and a 30% reduction of the temperature rise during motor operation.

A new piezoelectric ceramic longitudinal–torsional composite ultrasonic vibrator for wire drawing

“…As is well known, ultrasonic transducer has been developed relatively mature in recent decades, including many vibration mode, such as longitudinal [3], radial [4], torsional [5,6], bending [7], longitudinal-radial (L&R) composite [8], longitudinal-bending (L&B) composite [9,10], longitudinaltorsional (L&T) composite [11], bending-torsional (B&T) composite [12], and so on.…”

Ultrasonic spherical motor for compact inertially stabilized platforms

“…As it has been shown in previous papers ( [11], [12]), modal strain and stress are interesting optimization parameters when stimulating vibration mode of a piezoelectric beam at resonance. In our case, the modal strains of the two modes are very different and especially the areas of low strain for one mode correspond to areas of high strain for the other (see figure 8).…”

Actuation of Linear Ultrasonic Motors with a Square-wave Based Excitation Voltage

“…The stator body must have a resonant frequency that is equal or very close to this excitation frequency 2. The stator body must have an appropriate electrode-placement and voltage phase design to induce desired motion If the above two conditions are not satisfied, the energy of this excitation voltage would either dissipate as heat or induce some motion profile that may not be useful for the second stage of energy conversion [19,22]. Thus, an LUSM can only take advantage of an excitation voltage with multiple frequency components, if the stator body satisfies the two operating requirements with respect to each frequency component present in the excitation voltage.…”

“…This can be achieved when the contacting surface of the moving stage is made of a material with a stiffness in the same order of magnitude as that of the material of the stator driving tip, and the support block is made of a material with a stiffness that is much less than that of the stator body. For example, given that the stator body of the bimodal LUSM configuration is either made of piezoelectric ceramic fully [18,22] or of piezoceramic elements attached to a steel body [10], the material for the moving stage contacting surface can be steel or alumina ceramic.…”