Review on engineering structural designs for efficient piezoelectric energy harvesting to obtain high power output

Nowadays, with more electrical devices developed and applied in wide fields, efficient electrical energy generation is always one of the front-end and practical topics in engineering research. To disclose the possibility of obtaining high-power output from piezoelectric mechanism in the engineering structures, this study conducts a review of piezoelectric energy harvesting techniques from a structural design point of view. Piezoelectric power generation of these techniques can be significantly enhanced by increasing the operation frequency of piezoelectric materials and the strain level on them (up to Watt level). In this paper, following the general introduction of new energy solution requirements and piezoelectric mechanisms, novel ideas on piezoelectric energy harvesting from ambient vibration and natural resources are briefly reviewed. We then summarized and discussed the methodologies and mechanisms used to increase piezoelectric power generation and energy harvesting efficiency in detail. Following these methods, current studies on high-power piezoelectric harvesters are reviewed, described, and summarized to demonstrate the potential high-power generation from piezoelectricity. Taking advantage of the simple mechanism and design flexibility of the piezoelectric energy generation devices, additive manufacturing can be used to fabricate specially shaped piezoelectric meta-materials to further increase the strain and frequency applied to piezoelectric elements for obtaining higher energy harvesting efficiency in the near future.