Understanding the behavior of water-immersed membranes in the megahertz range is critical to develop novel acoustic metamaterials compatible with biomedical ultrasound applications. Herein, we study the influence of water on the resonance frequency and quality factor near the megahertz range of silicon nitride membranes fully immersed in water using laser Doppler vibrometry. The resonance frequency of silicon nitride membranes significantly decreases in water compared to air. For a 40 µ m wide membrane, the resonance frequency is reduced from 11.2 MHz in air to 1.24 MHz after immersion in water, which is confirmed by finite element method simulations. Our results indicate that the water mass loading plays a major role in the resonance frequency reduction, with a ratio of water mass to membrane mass of ##IMG## [http://ej.iop.org/images/0960-1317/30/12/125006/jmmabbcbaieqn1.gif] {$m_\mathrm{water}/m_\mathrm{membrane}\sim$} 10 2 and NAVMI factor...

中文翻译：

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兆赫兹范围内水中悬浮的氮化硅膜的频率和阻尼效应

了解兆赫兹级水浸膜的行为对于开发与生物医学超声应用兼容的新型声学超材料至关重要。在这里，我们使用激光多普勒振动法研究了水对完全浸入水中的氮化硅膜的兆赫兹范围附近的共振频率和品质因数的影响。与空气相比，氮化硅膜的共振频率在水中显着降低。对于40 µm宽的膜，浸入水中后，共振频率从空气中的11.2 MHz降低到1.24 MHz，这已通过有限元方法仿真得到了证实。我们的结果表明，水质量负载在共振频率降低中起主要作用，水质量与膜质量之比为## IMG ## [http：//ej.iop。