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 environment... read moreal vibrations,
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:
- DCA Citation Guide EndNote
