High Performance Pendulum Electromagnetic Energy Harvester Based on Model-Driven Optimization

Pendulum electromagnetic energy harvesters (PEEHs) offer a promising solution for powering Internet of Things (IoT) devices by converting biomechanical energy during human walking into electrical power in the micro- to milliwatt range. While the previous studies have primarily focused on optimizing electromagnetic parameters, structural factors—such as gear ratio—have received comparatively little attention, despite their significant influence on energy conversion efficiency. In this article, a coupled electromechanical model is developed by integrating magnetic field analysis via the magnetic scalar potential method and dynamic modeling using the Euler–Lagrange formulation. Model-driven optimization is performed to guide the design of a high-performance PEEH prototype. The magnetic field computation is validated through finite element analysis in COMSOL, and the coupled model is validated experimentally. Under operating conditions of 1.2 Hz frequency, 30° amplitude, and a 60 Ω load, the device achieves a peak output power of 4.03 mW and a normalized power density of 11.79 W/(m³·Hz·°). This article provides practical design guidance for the development of efficient, compact energy harvesters for wearable and IoT applications.