An energy harvesting system for passively generating power from human activities

This paper presents a complete, self-contained energy harvesting system composed of a magnetic energy harvester, an input-powered interface circuit and a rechargeable battery. The system converts motion from daily human activities such as walking, jogging, and cycling into usable electrical energy. By using an input-powered interface circuit, the system requires no external power supplies and features zero standby power when the input motion is too small for successful energy reclamation. When attached to a person's ankle during walking, the 100 cm(3) system prototype is shown to charge a 3.7 V, 65 mAh lithium-ion polymer battery at an average power of 300 mu W. The design and testing of the system under other operating conditions are presented herein.