A study of piezoelectric harvesters for low-level vibrations in wireless sensor networks

In this paper, we aimed to study the feasibility of using a piezoelectric harvester as a potential energy source to power microsystems, such as MicroElectroMechanical Systems (MEMSs) in wireless sensor networks (WSNs). An off-the-shelf piezoelectric bimorph was first tested to determine the power output under various resonant frequencies in the range of 42 to 103 Hz. The results showed that the piezoelectric bimorph generated greater power output at lower frequencies and higher accelerations, achieving an output of 3.072 mW from a vibrational source of 53 Hz and 1 g acceleration. The same system was also examined in response to low-level vibration source found in common environments, such as areas of residence, transportation and machinery to investigate the viability of its use in an environment with inconsistent vibrational frequency. Finally, a discussion is provided regarding the use of piezoelectric harvesters for WSNs and potential approaches to increase power output.