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.

Alternative energy sources like photovoltaic, fuel cell, wind, ultra capacitor, etc., are widely used in many applications such as in hybrid vehicles, micro grids etc. Combining two or more sources effectively, provides reliable power for the required application. Hence, the concept of hybrid energy system arises. In hybridization of energy systems, conventional sources and non-conventional sources are interfaced efficiently to drive the load. Two or more sources can be interfaced using different power electronic converters. Multiple Input DC/DC Converters (MIC) are one of the interfacing circuits used for hybridization of renewable and storage energy sources. In this paper, Dual input DC/DC converter is proposed which is useful in supplying the load from renewable and storage energy sources individually or simultaneously by connecting the two input sources in series. The two input sources to the converter used are photo-voltaic (PV) cell and a lead acid battery. Operation can be based on Buck, Boost or Buck-Boost modes. Using MATLAB/Simulink software, proposed converter is simulated.