VIBRATION ENERGY HARVESTING TECHNIQUE: A COMPREHENSIVE REVIEW

In order to minimize the requirement of external power source and maintenance for electric devices such as wireless sensor networks, the energy harvesting technique based on vibrations has been a dynamic field of studying interest over past years. Researchers have concentrated on developing efficient energy harvesters by adopting new materials and optimizing the harvesting devices. One important limitation of existing energy harvesting techniques is that the power output performance is seriously subject to the resonant frequencies of ambient vibrations, which are often random and broadband. This paper reviews important vibration-to-electricity conversion mechanisms, including theory, modelling methods and the realizations of the piezoelectric, electromagnetic and electrostatic approaches. Different types of energy harvesters that have been designed with nonlinear characteristics are also reviewed. As one of important factors to estimate the power output performance, the energy conversion efficiency of different conversion mechanisms is also summarized. Finally, the challenging issues based on the existing methods and future requirement of energy harvesting are also discussed.