Liquid crystal sensors for ultrasound detection

该研究小组最近表明，液晶可以用来制造超声被动检测传感器。该传感器提供超声波通过样品传播的可视图像；到目前为止，该传感器的演示主要集中在分析压电式换能器的谐振模式，以及通过样品的纵波的可视化。超声波位移较高的区域会导致液晶传感器被清除，这是肉眼可以看到的。对于穿过样品的波，任何阻碍路径的缺陷都将由未清除的区域显示出来。这项技术可以应用于许多领域。液晶材料的选择取决于工作温度，高温材料可以用来制作高温传感器。缺陷处瑞利波的增强可以用来识别油漆下的表面破裂缺陷，而不需要移除油漆；事实上，传感器将作为油漆的一部分嵌入。或者更简单地说，可以使用可拆卸传感器来分析新的压电式换能器的谐振模式。这项技术的TRL很低，但已经做好了开发的准备，为博士生提供了大量潜在的途径。该项目将确定关键的开发领域，研究潜在的应用，并开发传感器，使其可用于无损检测(NDT)。工作范围：确定关键应用和操作温度开发传感器以达到更高的TRL研究NDTEPSRC主题的潜力：能源(用于工厂检查)、工程、制造未来、物理科学

The research group has recently shown that liquid crystals can be used to make a passive detection sensor for ultrasound. The sensor gives a visual image of the propagation of ultrasound through the sample; demonstration of the sensor has thus far focused on analysis of the resonant modes of a piezoelectric transducer, and visualisation of longitudinal waves passing through a sample. Regions of higher ultrasonic displacement lead to clearing of the liquid crystal sensor, which can be seen by eye. For waves travelling through a sample, any defects blocking the path will be shown by regions which do not clear. This technology could be used in a number of areas. The choice of liquid crystal material depends on the temperature of operation, and high temperature materials could be used to make high temperature sensors. Enhancement of Rayleigh waves at a defect could be used to identify surface-breaking defects under a paint without removing the paint; in fact, the sensor would be embedded as part of the paint. Or more simply, a removable sensor could be used to analyse the resonant modes of new piezoelectric transducers. The technology is at a low TRL but is ready for exploitation, offering a large number of potential avenues for a PhD student. This project will identify the key areas for development, look at potential applications, and develop the sensors such that they can be used for non-destructive testing (NDT).Scope of Work: Identify key applications and temperatures of operationDevelop sensors to a higher TRLInvestigate potential for NDTEPSRC themes: Energy (for plant inspection), engineering, manufacturing the future, physical sciences