High-Performance Thin PTFE-Ni Metamaterial Absorber for Ultra-Broadband Applications

This study presents a high-performance, ultra-thin metamaterial absorber consisting of nickel resonator disks arranged in a 4 × 4 matrix on a polytetrafluoroethylene (PTFE) substrate. The novelty of the design lies in the integration of nickel—a cost-effective alternative to noble metals—and PTFE, whose excellent thermal stability enhances the overall performance of the metamaterial. Additionally, the simplified unit cell structure enables scalability and offers a practical alternative to conventional absorbers. The proposed metamaterial absorber achieves broadband absorption across the ultraviolet, visible, and infrared spectra. A systematic parametric analysis was conducted to optimize the structural parameters, maximizing absorption efficiency while maintaining minimal thickness. Numerical simulations performed in CST Studio Suite<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">®</sup> validated the optimized design, demonstrating an average absorption of 99.00% and a peak absorption of 99.36% within the 375–850 nm range. Given the elevated absorption rates achieved, the analysis range was extended to 300–3000 nm, and a genetic algorithm was employed to refine the geometric parameters. This optimization resulted in a stable absorption profile with an average efficiency of 98.98%, and a peak of 99.96%. This structurally simple design offers an advantage by combining cost-effective material selection with high broadband absorption performance.