Design and Optimization of Backfolded Piezoelectric Microenergy Generators
Typ
Examensarbete för masterexamen
Program
Applied mechanics (MPAME), MSc
Publicerad
2021
Författare
Sjöström, Viktor
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
A piezoelectric micro generator is a device that is intended to supply power to a wireless internet of
things (IoT) application. The generator accumulates power when undergoing mechanical stress by
vibration from the surroundings. The micro generator is able to sustain power to the application
without any external source of power.
The objective is to propose a design for two different models that is optimized with respect to
bandwidth, tolerance and low frequency spectrum. The first model is a single back folded beam
stucture, while the second is a double folded beam structure. The optimisation was carried out
with respect to resonant frequency analysis and frequency response of the design. The simulations
were carried out with the finite element software COMSOL multiphysics 5.6 and post processed
in Matlab. The total length, width of each beam and the length of the outer proof mass were
the major factors in improvement of the bandwidth, tolerance and frequency spectrum. The final
design of the single fold generator resulted in a bandwidth of 1181 Hz operating between 1100 and
2500 Hz with a tolerance of 236%. The final design of the double fold generator resulted in a
bandwidth of at least 2500 Hz operating between 900 and 2500 Hz with a tolerance of 27.6% and
50.1%. The bandwidth for both models were calculated with respect to a 0.1V threshold.
Beskrivning
Ämne/nyckelord
Energy generator , Piezoelectric , Bandwidth