Electromagnetic nondestructive evaluation using metamaterials sensor

The improvement of electromagnetic image quality of microscopic discontinuities in conductive pieces, damages of CFRP composites as well as metallic strip gratings from flexible printed circuits can be made using evanescent modes generated in slits, in spaces between carbon fibers and respectively in cracks. In order to generate the evanescent modes, plane electromagnetic waves, TMz polarized are used as excitation. The manipulation of the evanescent modes is made by means of metamaterials lens, conical Swiss roll type. The sensor allows the electromagnetic nondestructive evaluation of metallic strip grating, emphasizing the interruption of strips, CFRP delaminations due to impact with low energy as well as micrometric open at surface cracks in metallic pieces.