2D Materials-Based Ink to Develop Meta-Structures for Electromagnetic Interference (EMI) Shielding

2-D transition metal-chalcogenides which are semiconductor materials of the type MX₂, where M is a transition metal atom (like Ni, Fe, or Co) and X is a chalcogen atom (such as S or Se) are emerging class of materials which have excellent properties like atomic scale thickness, strong spin-orbit coupling, ability to form 2D nanosheets, direct band gap which 2D carbon based materials lack and many other mechanical and electronic properties. They are actively used in the fields like flexible electronics, opto-electronics, energy harvesting spintronics, personalised medicines etc. These properties make 2D materials lucrative for EMI shielding applications because of strong electronic polarization and enhanced dielectric loss. Research on hybrid materials like magnetic metal oxides with transition metal-chalcogenides like magnetic core-shell nanomaterials, Fe doped MoS₂, doped MoS₂-rGO composite, MoS₂/CoSe₂ hybrids, among several others suggests, these materials have high reflection loss. Further, magnetic transition metal dichalcogenides such as NiSe₂, CoSe₂ and their heterostructures, expediate multiple reflections and scattering of the incident wave, thereby elongating the course of transmission of the incident microwave, and thereby increasing dissipation efficiency, along with large specific surface area, which caters to EM absorption. In the present work inks have been developed base on these materials to make them versatile for several applications where it can be coated or screen printed.<br/><br/>The second part of this work involves development of meta structures using these paints as Radar absorbing materials. The tunability of material properties like permeability and permittivity by changing meta structure thickness and dimension allows the user to manipulate the electric and magnetic resonance at different frequencies independently, therefore, frequency selective structures can be made. In the present work we screen printed different geometries of structures using 2D material paints and tested for its capability as EMI shielding paint in X Band.