Beyond identical excitations: Multifrequency power response in piezoelectric energy harvester array
Part Of
Proceedings of SPIE - The International Society for Optical Engineering
Journal Volume
13946
Start Page
139460F
ISSN
0277786X
ISBN (of the container)
9781510698338
ISBN
9781510698338
Date Issued
2026-04-16
Author(s)
Abstract
This study investigates an array of piezoelectric energy harvesters connected in parallel and subjected to distinct excitation frequencies. Unlike conventional approaches that typically assume a single excitation frequency, the present work explores the dynamic interactions that arise when each harvester is driven at different frequencies yet remains electrically coupled. This scenario is highly relevant for powering wireless sensors distributed across various locations, where vibration sources are rarely single-Tone. An analytical model based on the equivalent load impedance of a single rectifier interface is developed to estimate the harvested DC power. Experiments are conducted using two harvesters connected in parallel, each of which is excited on a dual-shaker platform controlled via LabVIEW. The results reveal a two-dimensional DC power frequency response, where the x1-Axis corresponds to the excitation frequency of the first harvester and the x2-Axis corresponds to that of the second. The existence of the diagonal of this 2D map corresponds to the classical single-frequency response, thereby linking conventional and dual-frequency cases. As expected, high power occurs when both harvesters operate near their resonances. However, the two-dimensional framework further reveals the localized power peaks when only one harvester is at resonance, reflecting each harvester's contribution under frequency-mismatched excitation. Furthermore, a new bandwidth concept is introduced by defining the half-power boundary in the two-dimensional response, extending the classical bandwidth to dual-frequency systems. These findings provide a practical framework for broadband vibrational energy harvesting.
Event(s)
20th Active and Passive Smart Structures and Integrated Systems, 16 March 2026 - 18 March 2026, Vancouver
Subjects
Array
Distinct Excitation Frequencies
Equivalent Load Impedance
Multi-frequency Power Response
Piezoelectric Energy Harvesting
Publisher
SPIE
Type
conference paper