Recent Advances in Human Motion Excited Energy Harvesting Systems for Wearables

The development of wearable electronics and sensors is constrained by the limited capacity of their batteries. Therefore, energy harvesting from human motion is explored to provide a promising embedded sustainable power supply for wearable devices. Herein, the principles, development, and applications of human motion excited energy harvesters are reviewed. The energy harvesters are classified based on the human motions with distinguished characteristics: center of mass motion (COM), joint motion, foot strike, and limb swing motion. According to the motion characteristics, the principles, features, and limitations of different energy harvesters are discussed, and the power generation performances are compared. Finally, various self-powered applications enabled by embedded energy harvesters are introduced, so as to show the great potential of embedded energy harvesting systems in boosting the development of the wearables.