High-Performance Cycloid Inspired Wearable Electromagnetic Energy Harvester For Scavenging Human Motion Energy

Eco-friendly and wearable power sources are in high demand because of the hasty growth in smart wearable electronic devices including health care monitoring sensors. Here, we successfully designed and fabricated a high-performance cycloid-inspired wearable electromagnetic energy harvester (CEEH) for scavenging low frequency (≤5 Hz) human motion energy. The proposed CEEH introduces a cycloid curved structure as an energy harvester for the first time which provides the fastest descent for the freely rolling spherical magnet in the curve path, resulting an increment in the rate of cutting magnetic flux.

• Design and fabrication of a high-performance cycloid-inspired wearable electromagnetic energy harvester (CEEH).
• First-time use of a cycloid curved structure to maximize the velocity of a rolling magnet and increase magnetic flux cutting rate.
• Demonstrated ability to power commercial devices like a stopwatch and wristwatch from brief human motion.
• Performance is over 1.45 times higher compared to straight and circular designs.

A cycloid-inspired curved structure was designed to guide a freely rolling spherical magnet. The device's performance was evaluated through hand-shaking vibration tests and custom-made swinging arm tests to simulate human motions. The power output was measured under a 5 Hz vibration with an optimal load resistance.

The harvester delivers an average power of 8.8 mW at 5 Hz under an optimum load resistance of 104.7 Ω. It powered a commercial stopwatch for over 16 minutes and a wristwatch for over 34 minutes from just 5 seconds of hand motion. The cycloid design outperformed other geometric structures significantly.