In this paper, a summary of recent advancements in energy harvesting mechanisms is presented. These mechanisms are explained in three sections: electromagnetic, electrostatic, and piezoelectric. The energy density varies from different harvesting techniques where piezoelectric generates the highest, followed by electromagnetic and electrostatic. Piezoelectric and electromagnetic energy harvesters have a low voltage output compared to electrostatic energy harvesters and the maximum output power for electromagnetic, electrostatic, and piezoelectric can be up to 140mW, 50μW, and 12.5mW, respectively. The main drawback of piezoelectric energy harvesters is the price of the material, whereas other energy harvesters are less costly. The advancement on the applications of different energy harvesters can be seen in portable and implemented medical devices. They have a promising future for health monitoring systems and for cardiac implantations. It is expected that these technologies can be used for power generation in large-scale vibration applications such as vehicle suspension, civil structures, railway tracks, and human motion.