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

小型、灵敏、耐用、廉价、实时的传感器的开发受到了工程界研究和工业界的极大关注。压电传感器在从结构健康监测到化学和生物制剂识别的各种工程应用中显示出巨大的潜力。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。这些压电式传感器的应用广泛应用于各个领域。然而，检测机制是独特的，主要基于测量在材料中传播的弹性波的特征参数，如波速、幅度和衰减，以识别这些材料的物理变化。例如，这些压电传感器目前被用于结构的无损评估以检测裂纹，用于薄膜的表征以确定其厚度和模数，以及用于化学和生物表面声波装置以测量表面吸收的质量以识别化学和生物物种。本项目的目标是开发用于定量材料评价的新型集成压电声传感器。与传统的压电材料相比，压电纤维表现出更强的机电耦合，将被用来设计集成传感器。将进行理论和实验研究。理论研究将集中于发展能够描述压电传感器在静态和动态加载条件下的复杂机电行为的微观力学模型。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能。从长远来看，目前的研究成果不仅可以用于工程材料的评估，还可以用于化学和生物物种检测的下一代声学传感器的设计。

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.