Synthesis and characterization of Mn–Zn ferrite-based flexible penta-band metamaterial for sensing applications

This article presents the synthesis and characterization of a Mn–Zn ferrite based flexible penta-band metamaterial optimized for modern wireless and permittivity sensing applications, particularly emphasizing ceramic damage detection. The flexible substrate was prepared utilizing the sol–gel synthesis method for the design, where a SRR metamaterial unit cell was precisely designed and fabricated on this flexible substrate, followed by a comprehensive evaluation of its wireless and sensing aspects. The novel composite substrate combines PVA glue with a micro-scale Mn-Zn ferrite nanoparticle powder used as a filler, ensuring the metamaterial's flexibility while maintaining its essential characteristics. The structural and morphological assessments, including XRD and FESEM, demonstrated the potential of this composite for flexible substrate. The substrate achieved a dielectric constant of 5.9 and a loss tangent of 0.009, as measured using dielectric probe kit. The metamaterial demonstrates resonance in S, C, X, and Ku bands, with an excellent efficient transmission coefficient, where the resonate points are 2.70 GHz, 4.96 GHz, 8.88 GHz, 11.08 GHz, 12.76 GHz, respectively. The X-band resonate frequency is used for sensing applications. Furthermore, the novelty of the metamaterial showcased commendable bending performance across varying degrees, from 0° to 90° on different bendable ceramics due to its flexibility features. Finally, the presented flexible metamaterial offers promising options for modern wireless and permittivity sensing applications.