  In the last decade, an explosive attention has been paid to piezoelectric
harvesters due to their flexibility in design and increasing need to
small-scale energy generation. As a result, various energy review papers have
been presented by many researchers to cover different aspects of
piezoelectric-based energy harvesting, including piezo-materials, modeling
approaches, and design points for various applications. Most of such papers
tried to shed light on recent progresses in related interdisciplinary fields,
and to pave the road for future prospects of development of such technologies.
However, there are some missing parts, overlaps, or even some contradictions in
the review papers. In the present review of review articles, recommendations
for future research directions suggested by the review papers have been
systematically summed up under one umbrella. In the final section, topics for
missing review papers, concluding remarks on outlooks and possible research
topics, and strategy-misleading contents have been presented. The review papers
have been evaluated based on merits and subcategories and authors' choice
papers have been presented for each section based on clear classification
criteria.
