Two Bimorph Piezoelectric Energy Harvester for Vibrations.
Aryanpur, Rameen.
2012
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Abstract: This thesis
explores the effectiveness of a two bimorph piezoelectric energy harvester for
vibrations. Work in piezoelectric vibration energy harvesting has typically focused on
single member cantilevered structures with transverse tip displacement at a known
frequency, taking advantage of the optimal coupling characteristics of piezoceramics in
the 3-1 bending mode. Many environmental ... read morevibrations, however, are random or wideband,
rendering most cantilever energy harvesters sub-optimal. The purpose of the two bimorph
energy harvester was to widen the bandwidth of the power frequency response in
comparison to cantilever devices as well as to amplify it. Also, the device was designed
to prevent significant attenuation of the power response for non-transverse vibration
sources. The two bimorph device consisted of two hinged piezoceramic (PZT-5A) beams
poled for series operation. Each beam measured 31.8mm x 12.7mm x 0.38mm and consisted of
two layers of nickel-plated piezoceramic adhered to a brass center shim. The hinge
device consisted of two custom-machined aluminum attachments epoxied to the end of a
beam and connected using a 1.59mm diameter alloy steel dowel and torsion spring. Three
different configurations of the energy harvester were tested and their power frequency
response obtained. It was determined that the two bimorph device generated considerably
larger power than the cantilever across a wide low frequency range. This was a marked
achievement in that many devices in the literature do not perform well across wide bands
at low frequencies where most broadband environmental vibrations are observed. In
addition, the two bimorph device prevented significant attenuation of the power response
for base excitation not transverse to the structure, but did not introduce additional
resonant peaks.
Thesis (M.S.)--Tufts University, 2012.
Submitted to the Dept. of Mechanical Engineering.
Advisor: Robert White.
Committee: Robert Greif, and Luis Dorfmann.
Keyword: Mechanical engineering.read less - ID:
- 2801pt48b
- Component ID:
- tufts:20726
- To Cite:
- TARC Citation Guide EndNote
