Title

Optimizing a Piezoelectric Energy Harvester to Obtain Specific Eigenfrequencies

School Name

South Carolina Governor's School for Science & Mathematics

Grade Level

12th Grade

Presentation Topic

Engineering

Presentation Type

Mentored

Abstract

Piezoelectric material, which can transfer mechanical stress into electric energy, is a very simple way to harvest acoustic and mechanical vibrations. However, on its own, this material harvests an insignificant amount of energy. The resonance frequency, or the frequency at which piezoelectric material has the most mechanical stress, must be tuned to target frequencies, and create meaningful amounts of energy. A way in which this material can be tuned is through physical changes in the way the material is structured. In response to this, A harvester was created and optimized to react to frequencies under 100 Hz. 18 Hz, a common frequency in which a building's response footsteps occur was value that was used during the initial implementation. First, the effects of changing the dimensions of an object, specifically a cantilevered beam; on the eigenfrequency of the object were analyzed in order to find trends in the change of dimensions. An optimal shape for the energy harvester was found after through research of previous design and implementation of different designs, eventually settling on a spiral shaped coil with an inwards taper. Finally, the coil's dimensions were altered so that the resonance frequency of the object would be 18 Hz. The final dimensions of the coil were: A length of 30 mm, width of 10 mm, thickness of 1 mm, taper of -56.5 degrees, 2 revolutions and an overall height of 12 mm bringing the eigenfrequency of the coil to 18.022 Hz.

Location

Johns Hall 109

Start Date

3-28-2020 12:00 PM

Presentation Format

Oral Only

Group Project

No

COinS
 
Mar 28th, 12:00 PM

Optimizing a Piezoelectric Energy Harvester to Obtain Specific Eigenfrequencies

Johns Hall 109

Piezoelectric material, which can transfer mechanical stress into electric energy, is a very simple way to harvest acoustic and mechanical vibrations. However, on its own, this material harvests an insignificant amount of energy. The resonance frequency, or the frequency at which piezoelectric material has the most mechanical stress, must be tuned to target frequencies, and create meaningful amounts of energy. A way in which this material can be tuned is through physical changes in the way the material is structured. In response to this, A harvester was created and optimized to react to frequencies under 100 Hz. 18 Hz, a common frequency in which a building's response footsteps occur was value that was used during the initial implementation. First, the effects of changing the dimensions of an object, specifically a cantilevered beam; on the eigenfrequency of the object were analyzed in order to find trends in the change of dimensions. An optimal shape for the energy harvester was found after through research of previous design and implementation of different designs, eventually settling on a spiral shaped coil with an inwards taper. Finally, the coil's dimensions were altered so that the resonance frequency of the object would be 18 Hz. The final dimensions of the coil were: A length of 30 mm, width of 10 mm, thickness of 1 mm, taper of -56.5 degrees, 2 revolutions and an overall height of 12 mm bringing the eigenfrequency of the coil to 18.022 Hz.