Affiliations: [a] Institute of Intelligent Mechatronics Research,
Department of Instrument Science and Engineering, School of Electronic,
Information and Electrical Engineering, Shanghai Jiao Tong University,
Shanghai, China
Correspondence:
[*]
Corresponding author: Zhenyu Huang, Department of Instrument
Science and Engineering, School of Electronic, Information and Electrical
Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai
200240, China. Tel.: +86 21 3420 2725; Fax: +86 21 5474 4990; E-mail:
bighuang@sjtu.edu.cn
Abstract: Vibration-based piezoelectric energy harvesters usually work at
their resonant frequencies. The resonant frequencies can match, at most, one or
two ambient exciting frequencies. In order to freely design multiple operating
frequencies to match the given exciting frequencies, several oscillators were
attached on a piezoelectric cantilever in this paper, which is named as a
multi-mode piezoelectric energy harvester (MPEHer). A distributed-parameter
model of the MPEHer was established to predict its output power, and then a
lumped-parameter model was derived to determine its operating frequencies. With
the lumped-parameter model, the oscillator parameters can be searched for given
exciting frequencies. Considering the volume and weight limitation in
engineering application, optimizing procedures for the MPEHer were further
proposed. Following these procedures, an MPEHer limited by the
oscillator-to-cantilever mass ratio of 2.7 was designed for two given exciting
frequencies. Experiments show that, under the same input excitation, the
average output power of the designed MPEHer is increased by 82% compared with
that of a classical configuration, i.e. a piezoelectric cantilever with a tip
mass.
Keywords: Piezoelectric energy harvesting, multi-mode, cantilever, oscillator, resonance
