Theoretical and Experimental Investigation of a Rotational Magnetic Couple Piezoelectric Energy Harvester

Abstract

With the rapid development of Internet of Things (IoT) and the popularity of wireless sensors, using internal permanent or rechargeable batteries as a power source will face a higher maintenance workload. Therefore, self-powered wireless sensors through environmental energy harvesting are becoming an important development trend. Among the many studies of energy harvesting, the research on rotational energy harvesting still has many shortcomings, such as rarely working effectively under low-frequency rotational motion or working in a narrow frequency band. In this article, a rotational magnetic couple piezoelectric energy harvester is proposed. Under the low-frequency excitation (<10 Hz) condition, the harvester can convert low-frequency rotational into high-frequency vibrational of the piezoelectric beam by frequency up-conversion, effectively increasing the working bandwidth (0.5–16 Hz) and improving the efficiency of low-speed rotational energy harvesting. In addition, when the excitation frequency is too high (>16 Hz), it can solve the condition that the piezoelectric beam cannot respond in time by frequency down-conversion. Therefore, the energy harvester still has a certain degree of energy harvesting ability (18–22 Hz and 29–31 Hz) under high-frequency conditions. Meanwhile, corresponding theoretical analyses and experimental verifications were carried out to investigate the dynamic characteristics of the harvester with different excitation and installation directions. The experimental results illustrate that the proposed energy harvester has a wider working bandwidth benefiting from the frequency up-conversion mechanism and frequency down-conversion mechanism. In addition, the forward beam will have a wider bandwidth than the inverse beam due to the softening effect. In addition, the maximum powers of the forward and inverse beams at 310 rpm (15.5 Hz) are 93.8 μW and 58.5 μW, respectively. The maximum powers of the two beams at 420 rpm (21 Hz) reached 177 μW and 85.2 μW, respectively. The self-powered requirement of micromechanical systems can be achieved. Furthermore, this study provides the theoretical and experimental basis for rotational energy harvesting.

Development and performance evaluation of a wheel-type cantilevered piezoelectric rotational energy harvester via an unfixed exciting magnet

“…In recent years, piezoelectric rotational energy harvesters (PREH) have attracted many concerns due to the increasing demands upon data acquisitions, fault diagnosis, and real-time condition monitoring of rotating machinery to improve their health, safety and failure predictability (Chen et al, 2022; Sun et al, 2022; Zhang et al, 2018). To date, various PREHs were proposed to effectively exploit the rotational motion of shafts, wheels, gas, wind turbines, and automobile tires, etc (Nezami et al, 2019; Rezaei-Hosseinabadi et al, 2016; Yi et al, 2021).…”

“…This harvester Convert the vibration energy of automobile shock absorber into rotational kinetic energy through gears, which drives the magnet to excite the piezo-cantilever (Saleh et al, 2022). Sun et al proposed a rotational magnetic couple piezoelectric energy harvester, The harvester can convert low frequency rotation to high frequency and the vibration of piezoelectric beam can effectively increase the working bandwidth through frequency up-conversion (Sun et al, 2022). Similarly, Fu and Yeatman studied a methodology for designing a low-speed broadband PREH.…”

Investigation of a Novel Ultra-Low-Frequency Rotational Energy Harvester Based on a Double-Frequency Up-Conversion Mechanism

“…Therefore, there is an urgent need for a new type of power device that can provide a long-term energy supply. Energy harvesters, as emerging energy supply devices, leverage various mechanisms, such as piezoelectric [ 1 , 2 , 3 ], electromagnetic [ 4 , 5 ], triboelectric [ 6 , 7 ], and photovoltaic [ 8 , 9 ] effects, to convert mechanical energy, wind energy, solar energy, and other forms of ambient energy into electrical energy for external output. Among them, piezoelectric energy harvesters [ 10 , 11 , 12 ] have been employed in widespread applications due to their simple structure [ 13 , 14 ], long lifespan [ 15 , 16 ], and high adaptability [ 17 , 18 , 19 ] to environmental conditions.…”