Computational Analysis of Metal Foams for EMI Shielding Using COMSOL Multiphysics®
With the rapidly increasing usage of portable electronic devices and wireless communication technology, generation and propagation of electromagnetic energy are becoming one of the major concerns, not only because it affects the functionality and integrity of the electronics and their components, but also for the potential health risks for the human body [1, 2]. New cellular materials obtained by additive manufacture or 3D printing are showing their shielding potential from electromagnetic interference (EMI) due to their physical and energy absorption characteristics which, combined with a high electromagnetic wave reflection coefficient and good electrical conductivity [3], make them a useful material for this kind of application.
The objective of this work is to analyse the behavior of an open cell metal foam as an attenuator of electromagnetic radiation interference by developing a finite element model using computer simulation in COMSOL Multiphysics® 5.4. The geometry of the metal foam was designed in SolidWorks® and imported into COMSOL Multiphysics® by means of the CAD Import Module capabilities. The physical system is modeled in a medium composed of air, with the selected material being pure aluminium. The frequency analysis is carried out with the RF module by applying appropriate periodic, scattering, and port boundary conditions in the Electromagnetic Waves, Frequency Domain (emw) interface. S-parameters, electric field and power flow were calculated for a range of incident angles and frequency values. The computational simulation results show that this material possesses good attenuation capabilities against electromagnetic interference.
[1] A. Ameli, M. Nofar, S. Wang and C. B. Park, "Lightweight Polypropylene/Stainless-Steel Fiber Composite Foams with Low Percolation for Efficient Electromagnetic Interference Shielding," ACS Applied Materials & Interfaces, 6 n.14 , 1091-1100, (2014).
[2] L. B. Wang, K. Y. See, Y. Ling and W. J. Koh, "Study of Metal Foams for Architectural Electromagnetic Shielding," Journal of Materials in Civil Engineering, 24 n. 4, 488-493, (2012).
[3] Z. Xu and H. Hao, "Electromagnetic interference shielding effectiveness of aluminum foams with different porosity," Journal of Alloys and Compounds, 617, 207-213, (2014).
