{"title":"Shielding Effectiveness of Ferrofluid Layer in the Presence of Oscillating Magnetic Field","authors":"Huan-Kuang Kuan;Hsin-Chieh Hsieh;Yan-Hom Li","doi":"10.1109/TMAG.2025.3556849","DOIUrl":null,"url":null,"abstract":"This study investigates the effect of an oil-based ferrofluid layer subjected to oscillating magnetic fields on the shielding effectiveness (SE) of the electromagnetic wave (EMW) within 12.4–18 GHz. By leveraging the dynamic crest formations induced by varying the frequency from 0 to 105 Hz, the ferrofluid demonstrated significant adaptability and potential for effective electromagnetic interference (EMI) shielding. Results indicated that the ferrofluid crests exhibited pulsating behavior at lower oscillating frequencies of 1 Hz, enhancing SE to nearly 40 dB at 15.2 GHz. As the oscillation increased to 5 Hz, the crests displayed oscillatory instability, maintaining an SE peak of 37.7 dB at 17.6 GHz. For higher frequencies beyond 15 Hz, crest formation demonstrates a gradual diminishing behavior, transitioning into static or flat states, leading to a reduced SE. Additionally, the results revealed that thicker layers attenuate EM waves more effectively, even as crest dynamics become less pronounced. These findings highlight the capability of ferrofluid layers to achieve high EMI shielding through dynamic surface patterning, with thicker layers contributing to robust, adaptive, and flexible shielding solutions suitable for high-frequency electromagnetic environments.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 9","pages":"1-6"},"PeriodicalIF":1.9000,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"IEEE Transactions on Magnetics","FirstCategoryId":"5","ListUrlMain":"https://ieeexplore.ieee.org/document/10947180/","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENGINEERING, ELECTRICAL & ELECTRONIC","Score":null,"Total":0}
引用次数: 0
Abstract
This study investigates the effect of an oil-based ferrofluid layer subjected to oscillating magnetic fields on the shielding effectiveness (SE) of the electromagnetic wave (EMW) within 12.4–18 GHz. By leveraging the dynamic crest formations induced by varying the frequency from 0 to 105 Hz, the ferrofluid demonstrated significant adaptability and potential for effective electromagnetic interference (EMI) shielding. Results indicated that the ferrofluid crests exhibited pulsating behavior at lower oscillating frequencies of 1 Hz, enhancing SE to nearly 40 dB at 15.2 GHz. As the oscillation increased to 5 Hz, the crests displayed oscillatory instability, maintaining an SE peak of 37.7 dB at 17.6 GHz. For higher frequencies beyond 15 Hz, crest formation demonstrates a gradual diminishing behavior, transitioning into static or flat states, leading to a reduced SE. Additionally, the results revealed that thicker layers attenuate EM waves more effectively, even as crest dynamics become less pronounced. These findings highlight the capability of ferrofluid layers to achieve high EMI shielding through dynamic surface patterning, with thicker layers contributing to robust, adaptive, and flexible shielding solutions suitable for high-frequency electromagnetic environments.
期刊介绍:
Science and technology related to the basic physics and engineering of magnetism, magnetic materials, applied magnetics, magnetic devices, and magnetic data storage. The IEEE Transactions on Magnetics publishes scholarly articles of archival value as well as tutorial expositions and critical reviews of classical subjects and topics of current interest.