Piezoelectric energy harvesting from low-frequency deformation

The objective of this bachelor's thesis is to examine piezoelectric energy harvesting from low-frequency deformation using a bimorph-type piezoelectric diaphragm multilayer structure.

How much energy the sensors require has not been specified in any way. In this initial phase of the research, the potential of the concept is explored before considering the possible use of energy collectors for monitoring forest growth, health, and quality. This bachelor’s thesis is related to ongoing research at the University of Oulu, testing a proof of concept for an energy harvester that would generate energy for sensors from tree swaying.

This work goes through the basic idea of piezoelectricity and how it is used to harvest energy. My focus is on the harvester's type and its measurement results, particularly the comparison of different bimorph disc configurations (such as 150 µm and 200 µm steel discs) and the assembly and testing of a stacked five-layer harvester prototype, including its electrical load optimisation. I am observing how this harvester performed during different testing phases and the resulting data.

The results, which include successful power generation from the prototypes and the identification of key operational parameters, were promising and enable the next stage for testing the harvester in real-world conditions.