Dynamics of acoustic impedance matching layers in contactless ultrasonic power transfer systems
Dynamics of acoustic impedance matching layers in contactless ultrasonic power transfer systems
复制标题
DOI：
10.1088/1361-665x/ab6fe5
复制
发表时间：
2020-03-01
影响因子：
4.1
通讯作者：
Shahab, Shima
中科院分区：
文献类型：
--
作者：
Bakhtiari-Nejad, Marjan;Hajj, Muhammad R.;Shahab, Shima
超声功率传输系统中换能器材料与介质之间的声阻抗失配使换能带宽变窄，并且通过换能器与介质之间的边界处的渐进压力波的背反射引起损耗。捕获由于交织元件的阻抗失配引起的谐振和损耗对于推进这些系统的发展至关重要。我们提出了一个统一的方法，基于一系列的传输矩阵的乘法，以确定一个等效的声阻抗。该分析模型将发射器和接收器的特性与多个匹配层和单个经典四分之一波长层在受控设置中耦合，其目的是通过声阻抗失配缓解来最小化反射。由于材料层和介质中的超声衰减的损失也被考虑。接收器位置处的声场构成流体加载和电加载压电接收器的耦合电弹性方程的输入。实验进行识别的输入声压从一个圆柱形的发射器到一个接收器盘操作在33模式的压电。结果表明，显着的增强接收器的电功率输出时，实现一个两层的匹配结构。我们提出的结果示出了无量纲波数变化与特性阻抗的关系，其可用于计算材料的厚度，用于在任何期望的谐振频率下将超声功率传输系统与感兴趣的声学介质进行声学匹配，同时考虑任何类型的胶水或环氧树脂作为粘合层。导出的物理模型促进了高保真匹配系统的发展，增强了非接触式电力传输。
The acoustic impedance mismatch between transducer materials and medium in ultrasonic power transfer systems narrows the transduction bandwidth and causes losses through the back reflection of progressive pressure waves at the boundary between the transducers and medium. Capturing both resonances and losses due to impedance mismatch of interwoven elements is essential for advancing the development of these systems. We present a unified approach, based on the multiplication of a sequence of transfer matrices, to determine an equivalent acoustic impedance. The analytical model couples the properties of the transmitter and receiver with multiple matching layers and a single classical quarter-wave layer in controlled setups with the objective of minimizing reflections through acoustic impedance mismatch alleviation. Losses due to ultrasonic attenuation in the material layers and medium are also considered. The acoustic field at the receiver location constitutes the input to the coupled electro-elastic equations of the fluid-loaded and electrically-loaded piezoelectric receiver. Experiments are performed to identify the input acoustic pressure from a cylindrical transmitter to a receiver disk operating in the 33-mode of piezoelectricity. The results show significant enhancements in terms of the receiver's electrical power output when implementing a two-layer matching structure. We present the results showing non-dimensional wave number variations versus characteristic impedance, which can be used to calculate the materials' thicknesses for acoustically matching ultrasonic power transfer systems to an acoustic medium of interest at any desired resonant frequency while considering any type of glue or epoxy as the bonding layer. The derived physical models facilitate the development of high-fidelity matched systems with enhanced contactless power transmission.