Jin Yuqi, Yang Teng, Qi Yunlong
Department of Mechanical Engineering, University of North Texas, Denton, TX 76207, USA.
Department of Physics, University of North Texas, Denton, TX 76203, USA.
Polymers (Basel). 2025 Aug 15;17(16):2226. doi: 10.3390/polym17162226.
Soft organic gels are commonly used as tissue phantoms for experiments. In the mimic ultrasound imaging field, researchers are developing approaches to modify the acoustic properties of the gels. Introducing oil liquids and hard solid particles are two common methods to tune acoustic and mechanical properties of the soft gels. In this work, the acoustic wave energy loss mechanisms were studied in detail on Agar gel with both micro-Graphite and nano-Alumina particles. Via experimental measurements, the results show that the effective acoustic energy loss is comparable in these two recipes. However, temporal pulse elongation and scattering behaviors were distinguishable. To understand the sound attenuation mechanism in detail, numerical simulations in controlled conditions were conducted, from wavelengths longer than the particle diameter to wavelengths shorter than particles, and we compared perfect bonding and insufficient bonding between the hard particles surrounding gels. Comparing the experimental observations and numerical simulation results, the Agar gel with nano-Alumina presents stronger dispersion-induced energy loss than the Agar gel with micro-Graphite. On the contrary, the Agar gel with micro-Graphite shows more significant scattering-induced destructive interferences than the Agar gel with nano-Alumina.
柔软的有机凝胶通常用作实验的组织仿体。在模拟超声成像领域，研究人员正在开发改变凝胶声学特性的方法。引入油液和硬质固体颗粒是调节软凝胶声学和力学性能的两种常用方法。在这项工作中，详细研究了含有微米级石墨和纳米级氧化铝颗粒的琼脂凝胶中的声波能量损失机制。通过实验测量，结果表明这两种配方中的有效声能损失相当。然而，时间脉冲伸长和散射行为是可区分的。为了详细了解声衰减机制，在受控条件下进行了数值模拟，从波长大于颗粒直径到波长小于颗粒直径，并比较了凝胶周围硬质颗粒之间的完美结合和结合不足的情况。比较实验观察结果和数值模拟结果，含有纳米氧化铝的琼脂凝胶比含有微米级石墨的琼脂凝胶表现出更强的色散诱导能量损失。相反，含有微米级石墨的琼脂凝胶比含有纳米氧化铝的琼脂凝胶表现出更显著的散射诱导相消干涉。
