Investigation of an ultra-low frequency piezoelectric energy harvester with high frequency up-conversion factor caused by internal resonance mechanism

• Published in: Mechanical systems and signal processing Vol. 162; p. 108038
• Main Authors: Wu, Yipeng, Li, Sen, Fan, Kangqi, Ji, Hongli, Qiu, Jinhao
• Format: Journal Article
• Language: English
• Published: Berlin Elsevier Ltd 01.01.2022; Elsevier BV
• Subjects: Cantilever beams; Compound pendulum; Coupling coefficients; Energy harvesting; Extremely low frequencies; Frequency up-conversion; Internal resonance; Pendulums; Piezoelectric harvester; Piezoelectricity; Resonance; Resonant frequencies; Vibration energy harvesting; Piezoelectric harvester; Frequency up-conversion; Compound pendulum; Vibration energy harvesting; Internal resonance
• ISSN: 0888-3270; 1096-1216
• DOI: 10.1016/j.ymssp.2021.108038

[Display omitted] •The harvester can significantly up-convert the excitation frequency through 1:2:6 internal resonance mechanism.•The pendulum-like oscillator is designed as a key component to capture ultra-low frequency mechanical energy.•Elastic collision caused by mechanical stoppers can directly transfer the mechanical energy from the 1st swing DOF to 2nd vibration DOF.•The nonlinear harvester has advantages of ultra-low frequency and wideband vibration energy harvesting. The collection of ultra-low frequency mechanical energy that distributed in ambient environments remains challenging so far. This paper presents a frequency up-converting energy harvester based on a component pendulum, a pair of magnetic coupled cantilever beams, and two mechanical stoppers. The pendulum-like oscillator with ultra-low natural frequency can efficiently capture ambient mechanical energy and the designed 1:2:6 internal resonance mechanism can up-convert the frequency with a high conversion factor, presenting great potential for application in real-world systems with low vibration frequencies in the range of 1 to 5 Hz. Modeling and design are conducted, theoretical dynamic predictions are given and confirmed by experimental results. The proposed frequency up-converting harvester could generate a relatively high output power (about 2 mW) at a low excitation frequency and amplitude (around 2 Hz and 0.37 g). Moreover, the electromechanical coupling coefficient of the harvester can be further optimized, increasing the above-mentioned output power directly.