Liquid crystal sensors for ultrasound detection

该研究小组最近表明，液晶可用于制造超声波的被动检测传感器。该传感器提供了一个视觉图像的传播超声波通过样品;演示的传感器迄今为止集中在分析的谐振模式的压电换能器，并可视化的纵向波通过样品。较高超声位移的区域导致液晶传感器的清除，这可以通过眼睛看到。对于通过样品传播的波，任何阻挡路径的缺陷将由不清晰的区域显示。这项技术可以用于许多领域。液晶材料的选择取决于工作温度，高温材料可用于制造高温传感器。增强缺陷处的瑞利波可用于识别油漆下的表面破裂缺陷，而无需去除油漆;事实上，传感器将作为油漆的一部分嵌入。或者更简单地说，可以使用可拆卸的传感器来分析新压电换能器的谐振模式。该技术的TRL较低，但已准备好开发，为博士生提供了大量潜在的途径。该项目将确定开发的关键领域，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：确定关键应用和工作温度开发传感器，以更高的TR调查NDTEPSRC主题的潜力：能源（用于工厂检查），工程，未来制造，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