A Wearable Footstep Energy Harvester With Novel Dual-Clutch Mechanical Motion Rectification for Self-Powered Sensing

Wearable and autonomous sensing systems require efficient energy conversion under low-frequency, bidirectional mechanical excitations generated by daily human motion. This work presents a novel dual-clutch ratchet energy harvester (DREH) that converts bidirectional heel motions into unidirectional high-speed rotation, enabling direct DC power generation without conventional AC–DC rectification losses. The dual-clutch architecture ensures robust motion rectification under weak excitation and enables recovery of elastic potential energy during the liftoff phase, thereby improving effective energy utilization. A coupled dynamic–electromechanical model is developed to analyze the system behavior and predict electrical output. A compact prototype (86.4 cm³, 89 g) is fabricated and experimentally evaluated under pseudowalk and natural walking conditions. Experimental results show that elastic energy recovery increases output power by 59.5% at 0.3 Hz; at 6 km/h with a 75 Ω load, the prototype delivers 82 mW peak and 28 mW average power with a driving force below 14 N. System-level validation demonstrates continuous operation of a wireless sensing node, confirming the DREH as an effective self-sustained power source for wearable and industrial sensing applications.