Wide Frequency Range Vibration Energy Harvester Based on Asymmetric Springs
Gao Kai1, Peng Han2, Wang Shaojing1, Xu Peng1, Chen Yong2, Chen Jiahua2, Sun Hanyi2
1. State Grid Shanghai Electric Power Research Institute Shanghai 200437 China; 2. State Key Lab of Advanced Electromagnetic Engineering Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan 430074 China
Abstract With the rapid development of the Internet of Things, more and more wireless sensor networks and low-power electronic devices are widely used. At present, the primary power source of these devices is still traditional chemical batteries. These batteries have a low energy density, short lifespan, and environmental pollution. Moreover, replacing batteries for hundreds of millions of sensors requires many human and material resources. Therefore, obtaining energy from environmental energy, such as the sun, heat, wind, and vibration, as an alternative energy source for these devices has attracted considerable research interest. Among these energy sources, the vibration energy in the environment is widely regarded as one of the most concerned and researched energy sources because of its existence and not restricted by the environment. However, vibrations in the environment usually have broad frequency characteristics. In order to effectively harvest energy from these vibration sources, a wide frequency range energy harvester is required. This paper proposes a novel vibration energy harvester with a wide frequency range based on asymmetric springs. A new architecture of dual-asymmetric-springs with one magnet is discussed for wide frequency range coverage, flexible vibration pattern, and easy implementation. Firstly, the basic theory of electromagnetic power generation is introduced, and the physical characteristics of planar springs with bentbeams are investigated. The characteristic frequencies of different spring designs are presented, which is helpful for future design adjustments. It is concluded that the thicker the spring thickness is, the higher the characteristic frequency. The more spring beams are, the higher the characteristic frequency will be. The longer the spring beams are, the higher the characteristic frequency will be. Secondly, the architecture of a vibration energy harvester with asymmetric springs is explored. Vibration movement feature and electromagnetic conversion features are fully discussed with Finite-element analysis. The proposed architecture has three different vibration patterns, which can be adapted to different vibration environments. The time domain vibration movements are also shown. It is concluded that with asymmetric springs, two peak movement amplitudes appear at different frequencies. For the same spring, the amplitude at a lower characteristic frequency is higher than at a higher one. The lower the characteristic frequency is, the steeper the amplitude will be. The thicker the spring is, the two characteristic frequencies are more away from each other. Finally, the prototype of the proposed vibration energy harvester based on asymmetric springs is designed and fabricated. Magnetic of N38 is selected. The outer case and asymmetric springs are fabricated through 3D printing. The overall size of the prototype is 62 mm×32 mm×17 mm, with the diameter of a single spring of 25 mm, a magnet size of 40 mm×20 mm×5 mm, and a coil at one side of 3 mm. The prototype is tested using a vibration testing platform in the lab. When the thickness of the springs is 0.6 mm, and one is two beams and the other is three beams, the harvested voltage reach two peak value of 529.1 mV and 229.7 mV at the characteristic frequency of 34 Hz and 61 Hz, respectively. When the thickness of the springs is adjusted to 1 mm, and one is two beams and the other is three beams, the harvested voltage reaches two peak values of 632.6 mV and 244.9 mV at the characteristic frequency of 67 Hz and 115 Hz, respectively. The peak harvest power of the proposed vibration energy harvester based on asymmetric springs reaches 200 μW.
Gao Kai,Peng Han,Wang Shaojing等. Wide Frequency Range Vibration Energy Harvester Based on Asymmetric Springs[J]. Transactions of China Electrotechnical Society, 2023, 38(10): 2832-2840.
[1] Paradiso J A, Starner T.Energy scavenging for mobile and wireless electronics[J]. IEEE Pervasive Computing, 2005, 4(1): 18-27. [2] 谷渊. 面向物联网的无线传感器网络综述[J]. 信息与电脑(理论版), 2021, 33(1): 194-196. Gu Yuan.Overview of wireless sensor networks oriented to the internet of things[J]. China Computer & Communication, 2021, 33(1): 194-196. [3] Nadaf N, Preethi A.Review on waste heat energy harvesting using TEG: applications and enhance- ments[C]//2021 8th International Conference on Smart Computing and Communications (ICSCC), Kochi, Kerala, India, 2021: 334-339. [4] Brogan Q, O'Connor T, Ha D S. Solar and thermal energy harvesting with a wearable jacket[C]//2014 IEEE International Symposium on Circuits and Systems (ISCAS), Melbourne, VIC, Australia, 2014: 1412-1415. [5] Jushi A, Pegatoquet A, Le T N.Wind energy harvesting for autonomous wireless sensor net- works[C]//2016 Euromicro Conference on Digital System Design (DSD), Limassol, Cyprus, 2016: 301-308. [6] 赵争鸣, 王旭东. 电磁能量收集技术现状及发展趋势[J]. 电工技术学报, 2015, 30(13): 1-11. Zhao Zhengming, Wang Xudong.The state-of-the-art and the future trends of electromagnetic energy harvesting[J]. Transactions of China Electrotechnical Society, 2015, 30(13): 1-11. [7] Gou Wei, Fan Shiquan, Geng Li.Vibration energy harvesting system with MPPT for IoT appli- cations[C]//2018 1st Workshop on Wide Bandgap Power Devices and Applications in Asia (WiPDA Asia), Xi'an, China, 2019: 320-323. [8] Nammari A, Caskey L, Negrete J, et al.Fabrication and characterization of non-resonant magneto- mechanical low-frequency vibration energy harvester[J]. Mechanical Systems and Signal Processing, 2018, 102: 298-311. [9] Zhang Yulong, Wang Tianyang, Luo Anxin, et al.Micro electrostatic energy harvester with both broad bandwidth and high normalized power density[J]. Applied Energy, 2018, 212: 362-371. [10] Cha Y, Chae W, Kim H, et al.Energy harvesting from a piezoelectric biomimetic fish tail[J]. Renewable Energy, 2016, 86: 449-458. [11] Sun Hanyi, Peng Han, Xiao Hongfei, et al.An optimized design of compact self-powered module based on electromagnetic vibration energy harvester considering engineering feasibility[J]. IEEE Transa- ctions on Industry Applications, 2023, 59: 767-778. [12] 孙诗. 电磁式振动能量采集器非线性拓频方法研究[D]. 上海: 上海交通大学, 2018. [13] Aboulfotoh N A, Arafa M H, Megahed S M.A self- tuning resonator for vibration energy harvesting[J]. Sensors and Actuators A: Physical, 2013, 201: 328-334. [14] Hu Yating, Xu Yong.A wideband vibration energy harvester based on a folded asymmetric gapped cantilever[J]. Applied Physics Letters, 2014, 104(5): 053902. [15] Tang Qiaochu, Yang Yongliang, Li Xinxin.Repulsi- vely driven frequency-increased-generators for durable energy harvesting from ultra-low frequency vibra- tion[J]. The Review of Scientific Instruments, 2014, 85(4): 045004. [16] 王旭明, 代显智, 陈旺, 等. 碰撞式宽频振动能量采集器研究进展[J]. 陕西科技大学学报, 2020, 38(5): 150-156, 172. Wang Xuming, Dai Xianzhi, Chen Wang, et al.Research progress of collision broad band vibration energy harvester[J]. Journal of Shaanxi University of Science & Technology, 2020, 38(5): 150-156, 172. [17] Chen Yong, Peng Han, Cheng Zhipeng, et al.A planar PCB based energy harvester with voltage multi- plier[C]//2020 IEEE Energy Conversion Congress and Exposition (ECCE), Detroit, MI, USA, 2020: 975-980.
2023, Vol. 38 
