Zhang Tao, Ming Wei, Wen Zhijing, Yousaf Hira, Gong Pengjie, Li Lekang
College of Materials Science and Engineering, Xi'an University of Science and Technology, Xi'an 710054, China.
College of Science, Xi'an University of Science and Technology, Xi'an 710054, China.
Ultrason Sonochem. 2025 Jul 10;120:107457. doi: 10.1016/j.ultsonch.2025.107457.
To address the growing need for high-frequency tunable surface acoustic wave (SAW) devices in power ultrasound applications, this study uses finite element method (FEM) for designing and simulation of an AlN/GaN composite heterogeneous piezoelectric thin film structure fabricated on a sapphire substrate. The configuration employs a double piezoelectric layer approach to significantly improve electromechanical conversion efficiency, achieving an electromechanical coupling coefficient of 0.42%. The thickness of AlN/GaN is optimized to enable a systematic investigation of the dispersion characteristics and acoustic field distribution of Rayleigh and Sezawa waves within multilayer heterostructures. This optimization aims to facilitate the precision of ultrasonic fields, enhancing the high-frequency ultrasonic power density and the local acoustic field intensity. Simultaneously, the incorporation of SiO compensation layer into the AlN/GaN heterostructure results in the formation of periodic structure that exploits disparities in sound velocity and acoustic impedance. This facilitates enhanced acoustic energy, which significantly improves both the cavitation efficiency and the intensity of acoustic flow within the liquid-phase medium. The structured surface acoustic wave (SAW) devices exhibit high-frequency characteristics coupled with low insertion loss, rendering them highly suitable for deployment in high-power SAW microfluidic platforms aimed at achieving efficient liquid-phase microfluidic material transport and manipulation. These findings hold substantial value for the advancement of novel high-frequency power ultrasound devices, providing critical insights and implications for expanding the applications within the domains of microfluidics and biomedical acoustic manipulation.
为满足功率超声应用中对高频可调谐表面声波（SAW）器件日益增长的需求，本研究采用有限元方法（FEM）对在蓝宝石衬底上制备的AlN/GaN复合异质压电薄膜结构进行设计和仿真。该结构采用双压电层方法显著提高机电转换效率，实现了0.42%的机电耦合系数。对AlN/GaN的厚度进行了优化，以便系统研究多层异质结构中瑞利波和塞扎瓦波的色散特性和声场分布。这种优化旨在提高超声场的精度，增强高频超声功率密度和局部声场强度。同时，在AlN/GaN异质结构中引入SiO补偿层导致形成利用声速和声阻抗差异的周期性结构。这有利于增强声能，显著提高液相介质中的空化效率和声流强度。结构化表面声波（SAW）器件具有高频特性和低插入损耗，使其非常适合部署在旨在实现高效液相微流体材料传输和操作的高功率SAW微流体平台中。这些发现对新型高频功率超声器件的发展具有重要价值，为扩大微流体和生物医学声学操作领域的应用提供了关键见解和启示。
