A high-performance electromagnetic energy harvester for scavenging ultra-low frequency vibration energy of human foot movement

In our daily lives, low-frequency kinetic energy primarily manifests as vibrations. However, effective harnessing of low-frequency kinetic energy remains a formidable challenge. This paper proposes a rope-driven rotor that rotates around an axis and consists of an ultra-high-molecular-weight polyethylene (UHMWPE) wire wrapped around a metal shaft. The rotor can convert ultra-low frequency vibration/linear motion into rapid rotation by pressing the top at low frequencies and driving the rope for a quick release. The harvester can generate up to 36.25 mW power using a 0.1-mm-diameter UHMWPE wire as the rotor when periodically pressed down to 20 mm at a frequency of 1 Hz. A simple power generation floor is assembled, generating 28.58-mW power with a matching load at a frequency of 1.5 Hz. Moreover, the harvester can increase the charging voltage of a 0.47-F supercapacitor from 0 to 6.8 V within 10 min. In addition, the harvester can harvest energy through a light finger press motion, and the energy obtained can also support the continuous operation of multiple electronic devices concurrently. This study introduces an effective method for harvesting ultra-low frequency energy and has great prospects in the field of power generation floor and human movement energy harvesting.