Abstract
The approach to improve the output power of piezoelectric energy harvester is one of the current research hotspots. In the case where some sources have two or more discrete vibration frequencies, this paper proposed three types of magnetically coupled multi-frequency hybrid energy harvesters (MHEHs) to capture vibration energy composed of two discrete frequencies. Electromechanical coupling models were established to analyze the magnetic forces, and to evaluate the power generation characteristics, which were verified by the experimental test. The optimal structure was selected through the comparison. With 2 m/s2 excitation acceleration, the optimal peak output power was 2.96 mW at 23.6 Hz and 4.76 mW at 32.8 Hz, respectively. The superiority of hybrid energy harvesting mechanism was demonstrated. The influences of initial center-to-center distances between two magnets and length of cantilever beam on output power were also studied. At last, the frequency sweep test was conducted. Both theoretical and experimental analyses indicated that the proposed MHEH produced more electric power over a larger operating bandwidth.
Highlights
In recent years, wireless sensor networks and wearable electronic devices have become widely used and vibration energy harvesters have been proposed to convert ambient vibration energy into electrical energy and serve as alternative power sources
At the first resonance of experimental results, the output power (2.96 mW) and operating bandwidth (0.91 Hz) of the multi-frequency hybrid energy harvesters (MHEHs) respectively increased by 16.5% and 21.3%, as compared to that of the multi-frequency piezoelectric energy harvester (MPEH) (2.54 mW and 0.75 Hz)
Three types of magnetically coupled multi-frequency hybrid energy harvesters were proposed, modeled, fabricated, tested, and compared, in order to optimize the performance in capturing vibration energy with two discrete frequencies
Summary
Wireless sensor networks and wearable electronic devices have become widely used and vibration energy harvesters have been proposed to convert ambient vibration energy into electrical energy and serve as alternative power sources. The piezoelectric energy harvester (PEH) has drawn more and more research attention, due to its high energy density, easy fabrication, simple configuration, and so on. In order to enhance energy conversion performance and environmental adaptability, researchers pay much attention to broadband piezoelectric energy harvesting. Most of the research only focuses on a limited frequency range around a given excitation frequency. There are some vibration sources that contain two or more well-separated frequency ranges. The vibration frequency of a bus floor is 111 Hz while idling, but 10.8 Hz when running at moderate speed. Laptops exhibit two vibration frequencies of 43.2 and 90.2 Hz [8]. It is necessary to study multi-frequency energy harvesters
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
