A geometric parameter study of piezoelectric coverage on a rectangular cantilever energy harvester

Patel, R.; McWilliam, S.; Popov, A.A.

Abstract

This paper proposes a versatile model for optimizing the performance of a rectangular cantilever beam piezoelectric energy harvester used to convert ambient vibrations into electrical energy. The developed model accounts for geometric changes to the natural frequencies, mode shapes and damping in the structure. This is achieved through the combination of finite element modelling and a distributed parameter electromechanical model, including load resistor and charging capacitor models. The model has the potential for use in investigating the influence of numerous geometric changes on harvester performance, and incorporates a model for accounting for changes in damping as the geometry changes. The model is used to investigate the effects of substrate and piezoelectric layer length, and piezoelectric layer thickness on the performance of a microscale device. Findings from a parameter study indicate the existence of an optimum sample length due to increased mechanical damping for longer beams and improved power output using thicker piezoelectric layers. In practice, harvester design is normally based around a fixed operating frequency for a particular application, and improved performance is often achieved by operating at or near resonance. To achieve unbiased comparisons between different harvester designs, parameter studies are performed by changing multiple parameters simultaneously with the natural frequency held fixed. Performance enhancements were observed using shorter piezoelectric layers as compared to the conventional design, in which the piezoelectric layer and substrate are of equal length.

Citation

Patel, R., McWilliam, S., & Popov, A. (2011). A geometric parameter study of piezoelectric coverage on a rectangular cantilever energy harvester. Smart Materials and Structures, 20(8), Article 085004. https://doi.org/10.1088/0964-1726/20/8/085004

• Journal Article Type: Article
• Acceptance Date: Jun 1, 2011
• Publication Date: Jun 28, 2011
• Deposit Date: Feb 22, 2018
• Publicly Available Date: Feb 22, 2018
• Journal: Smart Materials and Structures
• Print ISSN: 0964-1726
• Electronic ISSN: 0964-1726
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 20
• Issue: 8
• Article Number: 085004
• DOI: https://doi.org/10.1088/0964-1726/20/8/085004
• Keywords: Energy harvesting, Piezoelectric beam, Finite element method
• Public URL: https://nottingham-repository.worktribe.com/output/707624
• Publisher URL: http://iopscience.iop.org/article/10.1088/0964-1726/20/8/085004/meta
• Additional Information: This is an author-created, un-copyedited version of an article published in Smart Materials and Structures. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at doi:10.1088/0964-1726/20/8/085004.