Development of Plucked Piezoelectric Energy Harvesting from Human’s Upper Limb Motion

This paper presents the design, modeling, and implementation of a plucked piezoelectric energy harvester (PEH) optimized for human elbow motion. The proposed system leverages the advantages of upper-limb biomechanics, particularly elbow flexion during walking, to generate electrical energy suitable for powering wearable electronics. A compact bimorph PZT-based PEH was selected and integrated with a mechanical plucking mechanism to enable frequency up-conversion from low-frequency body motion to high-frequency piezoelectric vibration. An electromechanical model predicting the electrical output and energy harvesting performance of a plucked PEH system was developed using Hamilton’s Principle and validated through experiments, showing strong agreement in voltage response and energy output. Implemented in MATLAB/Simulink, the model also served as a design tool for parametric optimization, allowing efficient tuning of system parameters prior to prototyping. Furthermore, parameter optimization through experimental tests identified a plucking distance of 0.16 mm and a load resistance of 800 Ω as optimal for the decided bimorph PZT in energy harvesting. The developed prototype successfully demonstrated repeatable energy generation ranging from 22–33 μJ per elbow movement cycle under simulated motion. This work offers a validated framework for future development of energy-autonomous wearable devices that are lightweight, compact, and ergonomically compatible.