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

Inspired by an electromagnetic hydropower station that contains a reverse polarized magnet, we proposed 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 single thin film. generalized theoretical model e-REHs free-standing (Fe-REH) sliding (Se-REH) operation modes derived evaluate their The key features affecting performance are the initial parasitic capacitances different connection schemes. Experimental results show that: power e-REH increased 392.2% compared those alone configurations, which fully agree obtained from model. For first time, intelligent thrust ball bearing designed fabricated self-powered self-sensing capabilities based on e-REH. rotation speed characterized response frequencies voltage Fast Fourier Transform instead amplitudes, exhibiting ultra-high frequency sensitivity 15.0 rpm/Hz good linearity R2 (coefficient determination) 99.9%. developed has potential applications high-precision rotation-speed sensing