Torque Arm Actuated Bi-Stable Buckled Energy Harvester Characterization
A bi-stable energy harvester utilizing PVDF strips driven via two torque arms with end masses and pseudo pinned in the middle is evaluated. A sinusoidal acceleration is applied to the base of the device with varying frequencies and magnitudes while the compression of the center beam is achieved by applying a small displacement to the center beam. Frequency sweeps will be done forwards as well as backwards to evaluate hysteresis performance. Peak voltages, natural frequencies, snap-through acceleration values, static actuation displacement values, and material properties for unknowns are derived experimentally.
While many parametric values such as beam length, compliance arm length, and proof mass can be varied, the focus of this study is on the effects of the compliance arm width on bi-stability switching and energy harvesting potential. For vibration-based energy harvesting, performance parameters such as power generated, power density, frequency broadening, frequency shifting, and optimal load impedance will be quantified. Results show that wider compliance arms decrease buckling amplitude, but increase the bi-stability switching regime and the overall power production. Current data also indicates that an optimal compression load exists for a given acceleration value.
KeywordsBi-stable structures Buckling Energy harvesting Piezoelectric materials Vibrations
The authors would like to acknowledge student support provided through the National Science Foundation, award number #1130528. In addition, the authors would like to thank Tim Varon and the University of Louisville, Department of Mechanical Engineering for their assistance in preparing this work.
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