Physics Department, Babes-Bolyai University, 400084 Cluj-Napoca, Romania.
Sensors (Basel). 2023 May 21;23(10):4939. doi: 10.3390/s23104939.
A research topic of equal importance to technological and application fields related to quartz crystal is the presence of unwanted responses known as spurious resonances. Spurious resonances are influenced by the surface finish of the quartz crystal, its diameter and thickness, and the mounting technique. In this paper, spurious resonances associated with fundamental resonance are studied by impedance spectroscopy to determine their evolution under load conditions. Investigation of the response of these spurious resonances provides new insights into the dissipation process at the QCM sensor surface. The significant increase of the motional resistance for spurious resonances at the transition from air to pure water is a specific situation revealed experimentally in this study. It has been shown experimentally that in the range between the air and water media, spurious resonances are much more attenuated than the fundamental resonance, thus providing support for investigating the dissipation process in detail. In this range, there are many applications in the field of chemical sensors or biosensors, such as VOC sensors, humidity sensors, or dew point sensors. The evolution of D factor with increasing medium viscosity is significantly different for spurious resonances compared to fundamental resonance, suggesting the usefulness of monitoring them in liquid media.
与石英晶体相关的技术和应用领域同样重要的研究课题是存在被称为寄生共振的不需要的响应。寄生共振受石英晶体的表面光洁度、直径和厚度以及安装技术的影响。本文通过阻抗谱研究与基频共振相关的寄生共振，以确定它们在负载条件下的演变。研究这些寄生共振的响应为 QCM 传感器表面的耗散过程提供了新的见解。在这项研究中，实验揭示了一个特殊情况，即在从空气向纯水过渡时，寄生共振的运动阻力显著增加。实验表明，在空气和水介质之间的范围内，寄生共振比基频共振衰减得厉害得多，因此为详细研究耗散过程提供了支持。在这个范围内，化学传感器或生物传感器领域有许多应用，例如 VOC 传感器、湿度传感器或露点传感器。与基频共振相比，寄生共振的 D 因子随介质粘度的增加而变化的情况明显不同，这表明在液体介质中监测它们的有用性。
