Department of Mechanical Engineering, The City College of the City University of New York, New York, NY 10031, USA.
Department of Chemistry and Biochemistry, The City College of the City University of New York, New York, NY 10031, USA.
Sensors (Basel). 2023 Jun 26;23(13):5911. doi: 10.3390/s23135911.
Blood viscosity is the defining health indicator for hyperviscosity syndrome patients. This paper introduces an alternative approach for the real-time monitoring of blood viscosity by employing a surface-horizontal surface acoustic wave (SH-SAW) device at room temperature. A novel bi-layer waveguide is constructed on top of the SAW device. This device enables the SAW sensing of liquid droplets utilizing a bi-layer waveguide, consisting of a zinc oxide (ZnO) enhancement layer and Parlyene C, that facilitates the promotion of the surface horizontal mode. The ZnO piezoelectric thin-film layer enhanced the local particle displacement and dielectric coupling while the Parylene C layer constrained the wave mode at the interface of the piezoelectric material and polymer material. The device was tested with a liquid drop on the SAW delay-line path. Both experimental and finite element analysis results demonstrated the benefits of the bi-layer waveguide. The simulation results confirmed that the displacement field of local particles increased 9 times from 1.261 nm to 11.353 nm with the Parylene C/ZnO bi-layer waveguide structure. The device demonstrated a sensitivity of 3.57 ± 0.3125 kHz shift per centipoise enabling the potential for high precision blood viscosity monitoring.
血液黏度是高黏度血症患者的重要健康指标。本文提出了一种在室温下利用水平表面声表面波（SH-SAW）装置实时监测血液黏度的新方法。在声表面波器件上构建了一种新型的双层波导。该装置利用由氧化锌（ZnO）增强层和 Parylene C 组成的双层波导实现了对液滴的声表面波传感，促进了表面水平模式的产生。ZnO 压电薄膜层增强了局部粒子的位移和介电耦合，而 Parylene C 层则约束了压电材料和聚合物材料界面处的波型。该装置在声表面波延迟线上进行了液滴测试。实验和有限元分析结果均表明双层波导具有优势。模拟结果证实，具有 Parylene C/ZnO 双层波导结构时，局部粒子的位移场从 1.261nm 增加到 11.353nm，增加了 9 倍。该装置的灵敏度为 3.57±0.3125kHz/厘泊，为高精度血液黏度监测提供了可能。
