Increasing the power of piezoelectric energy harvesters by magnetic stiffening

Autor: Tobias Hemsel, Matthias Hunstig, Walter Sextro, Waleed Al-Ashtari
Rok vydání: 2013
Předmět:
Zdroj: Journal of Intelligent Material Systems and Structures. 24:1332-1342
ISSN: 1530-8138
1045-389X
DOI: 10.1177/1045389x13483021
Popis: A piezoelectric cantilever beam with a tip mass at its free end is a common energy harvester configuration. This article introduces a new principle of designing such a harvester that increases the generated power without changing the resonance frequency of the harvester: the attraction force between two permanent magnets is used to add stiffness to the system. This magnetic stiffening counters the effect of the tip mass on the efficient operation frequency. Five set-ups incorporating piezoelectric bimorph cantilevers of the same type in different mechanical configurations are compared theoretically and experimentally to investigate the feasibility of this principle: theoretical and experimental results show that magnetically stiffened harvesters have important advantages over conventional set-ups with and without tip mass. They generate more power while only slightly increasing the deflection in the piezoelectric harvester and they can be tuned across a wide range of excitation frequencies.
Databáze: OpenAIRE