Taguchi Design of PZT-Based Piezoelectric Cantilever Beam with Maximum and Robust Voltage for Wide Frequency Range

Piezoelectric energy harvesting-an eco-friendly technology-is gaining more interest from researchers owing to its high power density. Among the various piezoelectric types, many studies have focused on the PZT-based piezoelectric cantilever beam because it can easily achieve the resonance effect compared to other types. In real applications, however, it is not easy to match the loading frequency with the resonance frequency owing to environmental factors. This prevents the application of piezoelectric energy harvesting to real life products because the efficiency of energy extraction decreases considerably outside the resonance frequency domain. In this research, the Taguchi design, which is an effective methodology used to improve product quality without controlling any noise factors, ensures that the PZT-based piezoelectric cantilever beam can obtain robust and high output voltage over a wide frequency range. The PZT-based piezoelectric cantilever beam should be implemented using the multi-response signal-to-noise ratio of the Taguchi design method because it has the two important responses, the output voltage and its deviation. Experiments are performed to measure the output voltage of various harvesters at the resonance frequency and several other frequencies. Based on the experimental results, the Taguchi design method is implemented considering the characteristics of the responses, and an optimal design combination is selected. As a result, the selected optimal combination results in a 9.86% output voltage reduction and an 18.14% decrease in voltage deviation.