Voronoi diagrams metallic mesh for transparent EMI shielding

Abstract

Recently, the transparent electromagnetic interference (EMI) shielding film, which is optical transparent, conductive, and EMI shielding, is widely employed in fields of display, solar cell, EMI shielding, and so on. Here, we utilized Voronoi diagram randomized metallic mesh and 3D printing technology to achieve transparent EMI shielding on curved surface. For the metal grid based on Voronoi diagram, one can realize highly homogeneous light transmission, with that optical performance is superior to that of regular and random quadrilateral mesh. The designed Voronoi diagram meshes were fabricated using aerosol jet (AJ) technology, which needs no mask and can achieve patterns on curved surfaces. The Voronoi metal meshes were fabricated on a 40 × 40 mm2 planar and a plano–convex lens with a diameter of 10 mm and a crown height of 3.7 mm. We investigated the optical transmittance of the Voronoi metal mesh grid and also the imaging performance of plano–convex lens with mesh grid. Furthermore, we analyzed the EMI shielding characteristics of the fabricated Voronoi mesh grids in the Ku-band (12–18 GHz) by using a vector network analyzer, which is higher than 23 dB. Therefore, the proposed Voronoi diagram and AJ technology can provide good diffraction uniformity and an effective method to fabricate the metal mesh grids on conformal surfaces.