Glass Fiber‐Reinforced Polyurethane Composite Structures with Integrated Piezoelectric Sensor Elements and Corresponding Electronics

In this contribution, process‐integrated fabrication and embedding of piezoelectric sensors based on free‐flowing starting components into glass fiber‐reinforced polyurethane composite structures and their characterization is presented. Main focus is investigating the influence of the polarization temperature on the resulting sensor properties. For this purpose, glass fiber‐reinforced polyurethane composite structures with integrated sensors are manufactured, polarized at different temperatures and then deformed by means of cyclic 3‐point bending tests. The charge signals generated by the integrated sensors are recorded by means of a specially developed measurement setup. The results show that the charges generated by the sensors can be significantly increased by polarization at elevated temperature. Furthermore, the development of associated sensor electronics is discussed and concepts as well as an implemented prototype of the integrated protection circuit for high voltage application during polarization are presented.