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

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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.