A high-power and high-efficiency mini generator for scavenging energy from human foot movement

Harvesting energy from human movement and converting it into electricity is a promising method to address the issue of sustainable power supply for wearable electronic devices. Using traditional energy harvesters for practical applications is difficult due to their low output power. In this paper, an energy harvester with high power and efficiency is reported based on the principle of electromagnetic induction. It adopts a tiny compound mechanism comprising symmetrical lever-sector gear, which can amplify the vertical displacement of the human heel of 1.44 times without affecting the flexibility and comfort of human movement. The lever-sector gear and gear acceleration mechanism can achieve high output power from the tiny vertical movements of the heel. The results demonstrated that the average power and energy harvesting efficiency of the device are 1 W and 63%, respectively. Moreover, combining a novel controllable electric switch and energy management circuit allows the energy harvester to be worn by individuals with different weights and functions as a continuous real-time power supply for various electronic devices (mobile phones, smartwatches, etc.). Therefore, this research provides a new approach for the highly efficient harvesting of human motion energy and sustainable power supply of wearable electronics.