Biomechanical energy harvesting

We recently developed a biomechanical energy harvester that generated substantial electricity during walking while requiring little extra effort. It took advantage of the fact that much of the displacement during walking occurs at body joints and harvested energy from knee motion. It selectively engaged power generation to assist the body in performing negative work, analogous to regenerative braking in hybrid cars. As muscle is ultimately the origin of energy available for biomechanical energy harvesting, the main purpose of this paper is to explain the physiological principles that guided our design process and to present a brief description of our device design and its performance.