Piezoelectric Energy Harvesting: a Systematic Review of Reviews

Abstract

An extensive description of research lines for future research is provided.• Statistics of publications and funding organizations are presented. KeywordsEnergy harvesting; piezoelectric; energy conversion; renewable energies; micro-electro-mechanical systems piezo-energy harvesting systems.An extensive search among electronic sources identified about 90 review papers in diverse applications related to the piezoelectric energy harvesting. As will be demonstrated later, such papers present many different concluding remarks corresponding to area of usage, materials, design approaches, and mathematical models. We tried to perform a very detailed searching procedure with too many keywords and by several search engines to cover all published review papers or the review papers in which "piezo" was not mentioned directly in the title.Statistics of publications during two recent decades excluding conference papers and conference reviews with the keyword "piezo AND energy harvesting" extracted from SCOPUS are shown in Fig. 2. Results from SCOPUS included overall number of 4435 documents, containing 874 open access papers, 130 book chapters, and 36 books. The National Natural Science Foundation of China, the Fundamental Research Funds for the Central Universities, and the National Research Foundation of Korea were the most frequent funding sponsors. Most common subject areas were engineering, material sciences, physics and astronomy, chemistry, and energy. An extrapolation shown in the figure anticipates publications of a huge number of articles (about 5000 articles a year) during the coming decade.Due to interdisciplinary nature of piezoelectric energy harvesting, prediction of behavior of the piezo-generators are related to different thermoelectro-mechanical sciences as well as material engineering. We have illustrated a systematic map of various aspects of piezo-energy harvesting and design in Fig. 3. Different branches of related sciences and applications include fabrication methods, hybrid systems, performance evaluation, size, usage methods, configurations, modeling aspects, economical points, energy sources, optimization, design of an electric interface, and selection of a proper material. All sub-branches in the figure will be discussed in subsections of the present paper. In all sections, the review articles have been presented in the order of the year of publication. This is so helpful to understand the revolutionary progressing level of the energy harvesting during the last decades. The outline of the paper is as follows. At the first section, the focus is on the reviews about the design process, structures, the material considerations, size effects, and the mathematical modeling challenges. At the second part of the article, the main theme of the review will be evaluating applications of the piezo-harvesters. The most common applications include vibrational energy sources, fluid-based harvesters, scavenging energy from ambient waste ener-