Piezoelectric power harvesting from mechanical strain

Abstract: Piezoelectric power harvesting is a field of active research. Most piezoelectric power harvesters are designed around harvesting energy from vibrations. This thesis is a feasibility study in collaboration with SKF to investigate whether or not a useful amount of power can be extracted from a piezoelectric tube mounted inside the roller of a bearing, based purely on harvesting power from mechanical strain instead of ambient vibrations, with the goal of replacing bulky single-use batteries as the power source for SKF's sensor roller technology. The methodology consisted of constructing and simulating a multiphysics model in COMSOL Multiphysics, and simulations were performed using three sets of parametric studies. Necessary material properties for the middle epoxy layer bonding the roller and piezo tube together were determined, before characterizing the piezoelectric behavior in relation to the magnitude of the applied load and the rotation of the roller. Simulation results indicate that approximately 0.64mW of power can be harvested from a single piezo tube under nominal operation in the test case, which is sufficient to power the sensor roller circuitry. In addition to simply replacing batteries as a power source, the technology opens up possibilites for more widespread adoption of sensor rollers in other applications.