Biomechanical Energy Harvesting: Generating Electricity During Walking with Minimal User Effort

• DOI: 10.1126/science.1149860
• Publication Date: 2008-02-07T23:48:20Z
• Authors: J. M. Donelan; Q. Li; V. Naing; J. A. Hoffer; D. J. Weber; A. D. Kuo
• Keywords: Electric generator; Mechanical energy; Regenerative brake

We have developed a biomechanical energy harvester that generates electricity during human walking with little extra effort. Unlike conventional human-powered generators use positive muscle work, our technology assists muscles in performing negative analogous to regenerative braking hybrid cars, where normally dissipated drives generator instead. The mounts at the knee and selectively engages power generation end of swing phase, thus assisting deceleration joint. Test subjects one device on each leg produced an average 5 watts electricity, which is about 10 times shoe-mounted devices. cost harvesting—the additional metabolic required produce 1 watt electricity—is less than one-eighth for generation. Producing substantial effort makes this method well-suited charging powered prosthetic limbs other portable medical