Broadband electromagnetic characterization of carbon foam to metal contact

We investigated how the electrical contact of carbon foam with metallic surface can reduce its shielding properties. The bubble structure of the foam does not ensure a good electrical contact with the metal, and it leads to a significant reduction of the shielding effectiveness. A finite element numerical simulation was carried out by adopting a bubble/pore model of the internal microstructure of the foam, recovered by means of scanning electron microscope images. Experimental tests were carried out by inserting carbon foam samples into a coaxial transmission line. Numerical results agree well with experimental result showing significant performance reduction with respect to an ideal electrical contact.