The authors applied the Finite Element Method (FEM) to analyze the electro-mechanical transformation and micro dynamical characteristics of a piezoelectric panel loudspeaker with triple layered piezoelectric ceramic slices in 2 × 2 rectangular arrangements. According to the simulated micro-vibration data, the authors built an acoustic analysis model combined with a linear superposition method to rapidly obtain the Sound Pressure Level (SPL) frequency response. FEM calculations of resonant modes, resonant frequencies, and the amplitude at the center of the diaphragm were in good agreement with measured values. The measured SPL frequency response agreed with the simulation, supporting the FEM model and the SPL frequency response calculation method proposed in this paper. In addition, an improved structure by addition of an elastic mat was illustrated and demonstrated to provide a smoother low-frequency SPL frequency response verified by both measurement and simulation methods.

The (K, Na) NbO3 (KNN) based multilayer ceramics with Ag0.7Pd0.3 inner electrode were fabricated by tape casting and cofiring processes. The ceramic–electrode inter-diffusion was studied by an energy dispersive X-ray spectroscopy with a precise spacial resolution attached to a transmission electron microscope. The results showed that the inter-diffusion occurred with elements migration through an interface zone. The distinct lattice image of the ceramic–electrode interface was obtained by a high-resolution transmission electron microscope. The lattice of KNN ceramic and Ag/Pd alloy interlaced with each other along the interface with slight lattice distortion. The results showed that the ceramic–electrode interface was very sharp with a width of about 5 nm. The sharp interface is good for the KNN-based multilayer ceramics with Ag/Pd electrode to be applied as promising substitutes for lead-based multilayer ones.

In this paper, a bimorph flexural piezoelectric ultrasonic transducer (PUT) with improved design principles for distance measurement was discussed. The profiles of vibration modes of PUT have been measured by laser Doppler interferometry and compared with finite element analysis (FEA) results. The results show the measurement modes and FEA calculated ones are well matched. The combination and comparison between FEA and advanced measurement tools have provided much help to the design and fabrication of PUT.

•A novel linear ultrasonic motor with four driving feet is proposed.•The proposed motor can realize high-speed moving and ultra positioning.•The proposed motor has two different operating modes.This paper presents a novel linear piezoelectric motor which is suitable for rapid ultra-precision positioning. The finite element analysis (FEA) was applied for optimal design and further analysis, then experiments were conducted to investigate its performance. By changing the input signal, the proposed motor was found capable of working in the fast driving mode as well as in the precision positioning mode. When working in the fast driving mode, the motor acts as an ultrasonic motor with maximum no-load speed up to 181.2 mm/s and maximum thrust of 1.7 N at 200 Vp-p. Also, when working in precision positioning mode, the motor can be regarded as a flexible hinge piezoelectric actuator with arbitrary motion in the range of 8 μm. The measurable minimum output displacement was found to be 0.08 μm, but theoretically, can be even smaller. More importantly, the motor can be quickly and accurately positioned in a large stroke.