Development of bipolar-charged electret rotatory power generator and application in self-powered intelligent thrust bearing

Tao, Kai, Zhao, Zhe, Yang, Yang, Wu, Jin, Li, Yunjia, Fan, Kangqi, Fu, Yong Qing, Chang, Honglong and Yuan, Weizheng (2021) Development of bipolar-charged electret rotatory power generator and application in self-powered intelligent thrust bearing. Nano Energy, 90 (Part A). p. 106491. ISSN 2211-2855

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Inspired by an electromagnetic hydropower station that contains a reverse polarized magnet, we proposed a new design methodology of electret rotatory energy harvester (e-REH) with bipolar-charged electrets for boosting its output performance. A selectively localized corona discharging method is invented to have both positive and negative ultra-high-resolution charges implanted into a single electret thin film. A generalized theoretical model of bipolar-charged e-REHs with free-standing (Fe-REH) and sliding (Se-REH) operation modes is derived to evaluate their performance. The key features affecting their performance are the initial and parasitic capacitances with different connection schemes. Experimental results show that: the output power of the bipolar-charged e-REH is increased to 392.2% compared to those of the positive alone and negative alone configurations, which fully agree with those obtained from the theoretical model. For the first time, an intelligent thrust ball bearing is designed and fabricated with its self-powered and self-sensing capabilities based on the bipolar-charged e-REH. The rotation speed of the bearing is characterized by the response frequencies of the output voltage by Fast Fourier Transform instead of the output voltage amplitudes, exhibiting an ultra-high frequency sensitivity of 15.0 rpm/Hz and a good linearity R2 (coefficient of determination) of 99.9%. The developed e-REH has potential applications for high-precision and self-powered intelligent rotation-speed sensing

Item Type: Article
Additional Information: Funding information: This research is supported by the National Natural Science Foundation of China Grant (Nos. 51705429 & 61801525), the Fundamental Research Funds for the Central Universities, Guangdong Natural Science Funds Grant (2018A030313400), Space Science and Technology Foundation, Shenzhen Research Plan (JCYJ20180306171637410), 111 Project No. B13044, UK Engineering and Physical Sciences Research Council (EPSRC) for support under Grant EP/P018998/1, International Exchange Grant (IEC/NSFC/201078) through Royal Society UK and the NSFC.
Uncontrolled Keywords: Electret power generator, Energy harvesting, Intelligent thrust bearing, Bipolar electrets, Self-powered sensing
Subjects: H600 Electronic and Electrical Engineering
Department: Faculties > Engineering and Environment > Mathematics, Physics and Electrical Engineering
Depositing User: John Coen
Date Deposited: 06 Sep 2021 09:16
Last Modified: 10 Sep 2022 08:00

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