In the last three decades, smart materials have become popular. The piezoelectric materials have shown key characteristics for engineering applications, such as in sensors and actuators for industrial use. Because of their excellent mechanical-to-electrical and vice versa energy conversion properties, piezoelectric materials with high piezoelectric charge and voltage coefficient have been tested in renewable energy applications. The fundamental component of the energy harvester is the piezoelectric material, which, when subjected to mechanical vibrations or applied stress, induces the displaced ions in the material and results in a net electric charge due to the dipole moment of the unit cell. This phenomenon builds an electric potential across the material. In this review article, a detailed study focused on the piezoelectric energy harvesters (PEH’s) is reported. In addition, the fundamental idea about piezoelectric materials, along with their modeling for various applications, are detailed systematically. Then a summary of previous studies based on PEH’s other applications is listed, considering the technical aspects and methodologies. A discussion has been provided as a critical review of current challenges in this field. As a result, this review can provide a guideline for the scholars who want to use PEH’s for their research.

With the breadth of applications and analysis performed over the last few decades, it would not be an exaggeration to call piezoelectric materials “the top of the crop” of smart materials. Piezoelectric materials have emerged as the most researched materials for practical applications among the numerous smart materials. They owe it to a few main reasons, including low cost, high bandwidth of service, availability in a variety of formats, and ease of handling and execution. Several authors have used piezoelectric materials as sensors and actuators to effectively control structural vibrations, noise, and active control, as well as for structural health monitoring, over the last three decades. These studies cover a wide range of engineering disciplines, from vast space systems to aerospace, automotive, civil, and biomedical engineering. Therefore, in this review, a study has been reported on piezoelectric materials and their advantages in engineering fields with fundamental modeling and applications. Next, the new approaches and hypotheses suggested by different scholars are also explored for control/repair methods and the structural health monitoring of engineering structures. Lastly, the challenges and opportunities has been discussed based on the exhaustive literature studies for future work. As a result, this review can serve as a guideline for the researchers who want to use piezoelectric materials for engineering structures.

Current engineering structures are effectively utilizing monitoring techniques based on electromechanical impedance (EMI) by employing piezoelectric sensors the EMI method is employed to monitor structural health of these systems. This study focuses on performing numerical analyses for structural health monitoring in healthy and damaged aluminium structures. For numerical analysis a finite element-based program in ANSYS commercial tool was utilized to model the beams made of undamaged and damaged aluminium. Additionally parametric studies were done to determine the impedance signal in aluminium structures with Lead-Zirconate-Titanate (PZT). The results obtained indicate that the finite element (FE) modeling with EMI technique is valuable for health monitoring of structures with impedance for healthy and damaged aluminium structures.

Piezoelectric transducers have attracted considerable attention in structural repair and health monitoring because of their dual actuation and sensing capabilities. This review critically examines their application in repairing and monitoring damaged engineering structures, particularly those containing cracks, notches, delamination, and debonding. First, analytical, numerical, and experimental approaches for piezoelectric-based structural repair are evaluated, with emphasis on crack suppression, stress intensity factor reduction, stress concentration control, and structural response improvement. The effects of actuator location, applied voltage, patch geometry, adhesive prop-erties, loading conditions, and optimization techniques are also discussed. The review then examines piezoelec-tric-based structural health monitoring techniques, including guided Lamb waves, electromechanical impedance, vibration-based sensing, sensor placement, and machine-learning-assisted damage assessment. The critical analysis shows that numerical investigations dominate the existing literature, whereas experimental validation, mixed-mode fracture studies, and long-term performance assessments remain limited. Finally, current research gaps, challenges, and future opportunities for intelligent and adaptive engineering structures are identified.