Advanced technologies for Piezoelectric Sensors in SHM systems: a review

The scientific and technical challenges posed by the new era of space flights for the explora-tion of planets is one of the main drivers for advanced structural health monitoring (SHM) systems. The main componenents of these systems and their interaction are reported in the illustration in Figure 1. This review is focused on the analysis of the state of the art of sensors for guided ultrasonic waves for the detection and localization of impacts. The recent develop-ments in sensor technologies are then reported [1][2][3]. The physical phenomena that are re-lated to impact event and the related main phys-ical quantities are then introduced to discuss their importance in the development of the hardware and software components for SHM systems. In this context, the analysis of the front-end electronics is deepened, the type of data transmission both in terms of wired and wireless technology and of online and offline signal processing [4]. The integration aspects of sensors for the creation of networks with auton-omous nodes with the possibility of powering through energy harvesting devices and the em-bedded processing capacity is also reported. Finally, the emerging sector of processing tech-niques using deep learning and artificial intelli-gence concludes the review by indicating the potential for the detection and autonomous characterization of the impacts and related damages.