Study of new intergrated sensor systems using piezoelectric fibre composites for material evolution

小型，灵敏，耐用，廉价，实时传感器的发展已经受到工程研究和工业界的相当大的关注。压电传感器在各种工程应用中显示出巨大的潜力，从结构健康监测到化学和生物制剂识别。它们的高机电耦合和快速响应使机械测量能够有效地转换为高灵敏度和高分辨率的电信号。这些压电传感器的应用广泛地扩展到不同的领域。然而，检测机制是独特的，并且主要基于测量在材料中行进的弹性波的特征参数，例如波速、振幅和衰减，以识别这些材料的物理变化。这些压电传感器目前用于，例如，在结构的无损评估，以检测裂纹，在表征薄膜，以确定其厚度和模量，并在化学和生物表面声波装置，以测量在表面吸收的质量，以确定化学和生物物种。本项目的目标是开发用于定量材料评估的新型集成压电声传感器。压电纤维具有比传统压电材料高得多的机电耦合，将用于设计集成传感器。将进行理论和实验研究。理论研究将集中在能够描述静态和动态加载条件下的压电传感器的复杂的机电行为的微机械模型的发展。 实验研究将包括新传感器的测试和应用。利用这种集成的传感器系统，将开发一种新的技术来定量评估材料的内部性质。从长远来看，目前的研究成果可用于设计下一代声传感器，不仅用于工程材料评估，还用于化学和生物物种检测。

The development of small, sensitive, durable, inexpensive, real-time sensors has received considerable attention from research and industrial communities in engineering. Piezoelectric sensors show great potential in various engineering applications, ranging from structural health monitoring to chemical and biological agent identification. Their high electromechanical coupling and quick response enable the effective conversion of mechanical measurements into electric signals with high sensitivity and high resolution. The applications of these piezoelectric sensors are widely spread into diverse areas. The detection mechanism is, however, unique and based primarily on measuring characteristic parameters of elastic waves traveling in materials, such as wave speed, amplitude, and attenuation to identify physical changes of these materials. These piezoelectric sensors are currently used, for example, in the nondestructive evaluation of structures to detect cracks, in the characterization of thin films to determine their thickness and modulus, and in chemical and biological surface-acoustic-wave devices to measure the mass absorbed at the surface to identify chemical and biological species. It is the objective of the current project to develop new integrated piezoelectric acoustic sensors for quantitative material evaluation. Piezoelectric fibres, which show much higher electromechanical coupling than traditional piezoelectric materials, will be used to design the integrated sensors. Both theoretical and experimental studies will be conducted. The theoretical study will be focused on the development of micromechanical models capable of describing the complicated electromechanical behaviour of the piezoelectric sensors under both static and dynamic loading conditions. The experimental study will encompass the testing and application of the new sensors. Using such an integrated sensor system, a new technique will be developed to quantitatively evaluate the interior properties of materials. In the long term, the outcome of the current research could be used in the design of the next generation of acoustic sensors not only for engineering materials evaluation but also for chemical and biological species detection.