Development of 3D Structures as Radar Absorbing Metamaterials Fabricated by the 3D Printing Process

Abstract

The potential of three-dimensional (3D) metamaterials to revolutionize stealth technology and reduce automotive false imaging has sparked significant interest.

Honeycomb structures coated with radar-absorbing materials (RAM) are examples of 3D metamaterials suitable for radar-absorbing applications.

We have designed four innovative 3D honeycomb structures with various inner wall shapes based on 3D metamaterials using SOLIDWORKS software in this work. A finite element analysis was conducted on each structure using COMSOL software to optimize the geometry of each honeycomb structure. 3D printing technology was used to print the optimized honeycomb structures. These structures, with their unique features and outstanding mechanical properties (e.g., they can withstand a pressure load of 80 KN and up to 30 KN extension load), serve as a testament to the potential of 3D metamaterials in radar absorption technology, sparking excitement for the future of this field.

Various nanocomposites of RAM materials have been fabricated and characterized based on multi-walled carbon nanotubes (MWCNTs), iron oxides (Fe3O4), and MXene. Such nanocomposites with optimized compositions exhibit excellent electromagnetic and mechanical properties and can significantly absorb radar waves in the X-band frequencies.

The fabricated RAM nanocomposites, designed for practical application, are spray-coated on the 3D-printed honeycomb structures layer-by-layer. We start with MWCNT/CMC, which has the highest electrical conductivity; then the middle layer, MWCNT/CMC/Fe3O4, which shows the best radar absorbing ability; and finally, the MXene/MWCNT/CMC/Fe3O4 layer, which was exposed to the radar waves due to its low radar wave reflectivity.

Free-space measurements were conducted on the coated honeycomb structures to measure the scattering parameters in the X-band frequency range from 8.2 GHz to 12.4 GHz. Then, the Reflection Loss and the Absorbance were calculated. The four honeycomb meta-structures absorbed over 95% of radar waves in the X-band frequencies.

The results prove that the metamaterial honeycomb structures are promising candidates for radar absorption technologies.

Date of Award	11 Dec 2024
Original language	American English
Supervisor	Daniel Choi (Supervisor)