The materials of shielding for RF electromagnetic waves: A systematic review

Background It is impossible to conceive a modern and social man who does not use mobile devices and/or computers with WiFi function. Electromagnetic waves are known to have harmful effects for both sensitive electronic equipment and for human health. Objectives: The purpose of this paper is to review the materials that are used for shielding of RF electromagnetic waves. Materials/Patients and Methods: The present systematic review was conducted by searching English language articles from sources such as Medline, International Medical Sciences, Scopus, Web of Science, PubMed, Google Scholar, DOAJ, EBSCO-CINAHL. Included criteria were all observational studies that conducted during 2002-2014. Case report, case series, letter to editor, and patent studies were excluded. Boolean operators were OR and AND. Related Boolean operators and keywords were selected to change the search strategies. There is no language limitation during the search of the database. Results: 73 related articles were found. After reviewing article titles, 44 unrelated articles and 10 patents article were removed, and 19 articles were evaluated of which 12 articles were duplicated. Finally, 7 articles were selected for final analysis. The results have been shown relationship between the absorption and reflection of electromagnetic waves by using different thicknesses of needle-punched non-woven fabrics with fibers and copper cables with stainless steel protective fabrics, cotton composite layer containing nanoparticles of Ni and Co, compact layer of nanoparticles of cobalt, iron carbonyl hybrid composite, carbonyl iron ferrite hybrid composite. Among the various materials used in the studies, using a combination of composite laminated linen Ni and Co nanoparticles resulted in the highest protection up to 70 dB by reducing the reflection coefficient down to - 25 dB in the frequency range of 1-118 GHz. Conclusion: According to this reviewed articles, special attention has been taken to the use of knitwear technology and the nanoparticles technology to absorb electromagnetic waves. In the future, these materials can be used in mobile phones without reducing sensitivity of communication.