13-09-2017, 02:53 PM
To minimize the need for external power supply and the maintenance of electrical devices such as wireless sensor networks, the vibration-based energy collection technique has been a dynamic field of study of interest in recent years. An important limitation of existing energy harvesting techniques is that the output power output is seriously subject to the resonant frequencies of ambient vibrations, which are usually random and broadband. To solve this problem, researchers have focused on developing efficient energy harvesters by adopting new materials and optimizing collection devices. In particular, among these approaches, different types of energy harvesters have been designed with consideration for non-linear characteristics, so that frequency bandwidth can be expanded for efficient energy harvesting of power harvesters. This article reviews three important and important mechanisms of conversion of vibration to electricity, its theory or methods of design and potential applications in the literature. As one of the important factors for estimating output power output, we also summarize the energy conversion efficiency of different conversion mechanisms.