Ahmad Iftikhar, Hassan Adnan, Anjum Muneeb Ullah, Malik Sohail, Ali Tashfeen «Ambient Acoustic Energy Harvesting using Two Connected Resonators with Piezoelement for Wireless Distributed Sensor Network» Акустический журнал, 65, № 5, с. pp. 471-477 (2019)

In this article, an acoustic energy harvester (AEH) is conceptualized, designed, fabricated and tested. The developed AEH (DAEH) consists of two Helmholtz cavities (HCs) and a commercially available piezoelement. The HCs were fabricated from Teflon material using conventional machining operations. An indigenous test bench for in-lab characterization of DAEH has also been developed. Various experiments were performed to experimentally record the frequency response function, loading and power characteristics. Additionally, the in-lab and open-air characterization of the DAEH is also reported. Furthermore, the proposed prototype of DAEH is compared on the basis of various benchmarks with the prototypes available in the literature. The experimental results indicate a maximum power density of 32.7 μW/cm³ at 130 dB.

Ahmad Iftikhar, Hassan Adnan, Anjum Muneeb Ullah, Malik Sohail, Ali Tashfeen «Ambient Acoustic Energy Harvesting using Two Connected Resonators with Piezoelement for Wireless Distributed Sensor Network» Акустический журнал, 65, № 5, с. pp. 471-477 (2019)

In this article, an acoustic energy harvester (AEH) is conceptualized, designed, fabricated and tested. The developed AEH (DAEH) consists of two Helmholtz cavities (HCs) and a commercially available piezoelement. The HCs were fabricated from Teflon material using conventional machining operations. An indigenous test bench for in-lab characterization of DAEH has also been developed. Various experiments were performed to experimentally record the frequency response function, loading and power characteristics. Additionally, the in-lab and open-air characterization of the DAEH is also reported. Furthermore, the proposed prototype of DAEH is compared on the basis of various benchmarks with the prototypes available in the literature. The experimental results indicate a maximum power density of 32.7 μW/cm³ at 130 dB.

Alia A. «Application of Discrete Huygens Method for Diffraction of Transient Ultrasonic Field» Акустический журнал, 64, № 1, с. pp. 10-17 (2018)

Several time-domain methods have been widely used to predict impulse response in acoustics. Despite its great potential, Discrete Huygens Method (DHM) has not been as widely used in the domain of ultrasonic diffraction as in other fields. In fact, little can be found in literature about the application of the DHM to diffraction phenomenon that can be described in terms of direct and edge waves, a concept suggested by Young since 1802. In this paper, a simple axisymmetric DHM-model has been used to simulate the transient ultrasonic field radiation of a baffled transducer and its diffraction by a target located on axis. The results are validated by impulse response based calculations. They indicate the capability of DHM to simulate diffraction occurring at transducer and target edges and to predict the complicated transient field in pulse mode.

Anisimkin V.I., Verona E., Kuznetsova A.S., Osipenko V.A. «Acoustic Wave Propagation Along Piezoelectric Plate Coated with Piezoelectric Films» Акустический журнал, 65, № 2, с. pp. 171-177 (2019)

A novel solid state structure consisting of piezoelectric plate sandwiched between two piezoelectric films is suggested as propagation medium for acoustic waves. Considering, as an example, quartz plate coated with AlN film and with AlN film together with ZnO film, the main characteristics of the Lamb and SH acoustic modes are numerically calculated and compared with each other. It is shown that i) the range of acoustic parameters achievable in structures is wider than that is for an uncoated plate, ii) generation of waves in the plate with one film is accomplished by 12 transducer configurations, while there are 32 configurations to excite the same waves in two film structure, iii) dispersion of the wave velocities and coupling constants depend on the mode order, mode type, film thickness, plate thickness, and transducer configuration. This property makes selection of appropriate modes more flexible. Results of calculations are partially verified experimentally.

Ahmad Iftikhar, Hassan Adnan, Anjum Muneeb Ullah, Malik Sohail, Ali Tashfeen «Ambient Acoustic Energy Harvesting using Two Connected Resonators with Piezoelement for Wireless Distributed Sensor Network» Акустический журнал, 65, № 5, с. pp. 471-477 (2019)

In this article, an acoustic energy harvester (AEH) is conceptualized, designed, fabricated and tested. The developed AEH (DAEH) consists of two Helmholtz cavities (HCs) and a commercially available piezoelement. The HCs were fabricated from Teflon material using conventional machining operations. An indigenous test bench for in-lab characterization of DAEH has also been developed. Various experiments were performed to experimentally record the frequency response function, loading and power characteristics. Additionally, the in-lab and open-air characterization of the DAEH is also reported. Furthermore, the proposed prototype of DAEH is compared on the basis of various benchmarks with the prototypes available in the literature. The experimental results indicate a maximum power density of 32.7 μW/cm³ at 130 dB.