Page 144 - MSAM-4-3

Materials Science in Additive Manufacturing Sunflower-inspired microwave-absorbing metastructure

A

B

C

D

Figure 12. Simulated electric field (|E|, left) and magnetic field (|H|, right) distributions of the sunflower-inspired metastructure at absorption peak
frequencies: (A) 4.66 GHz, (B) 8.80 GHz, (C) 13.25 GHz, and (D) 17.04 GHz, illustrating the evolution of the field localization and resonance behavior

A The simulated and experimentally measured RL curves
at the incident angle of 0° under TE polarization are
compared in Figure 14. Overall, the measured results
exhibit a trend consistent with the simulations, confirming
the validity of the electromagnetic modeling approach.
B However, minor discrepancies are observed between
the measured and simulated data. These deviations are
primarily attributed to several factors: the small unit size,
dimensional inaccuracies, slight warping at the base of the
printed sample, and surface roughness caused by the step

C effect inherent to the FDM process. These imperfections
can lead to additional electromagnetic wave scattering and,
consequently, diminished absorption efficiency.
The measured EAB (12.13 GHz) spans from 5.87 to
18 GHz, which is slightly narrower than the simulated
D bandwidth. In the 2 – 5.87 GHz range, the measured RL
does not reach −10 dB, unlike in simulations (Figure 14).
This discrepancy is potentially due to differences in
the incident angle. While simulations assumed normal
incidence, the experimental setup employed side-by-side
Figure 13. Simulated power loss density distributions of the metastructure horn antennas, resulting in a non-zero incident angle and
at varying absorption peak frequencies: (A) 4.66 GHz, (B) 8.80 GHz,
(C) 13.25 GHz, and (D) 17.04 GHz, showing the shift of energy dissipation reduced absorption. Nonetheless, the metastructure still
from the structure’s center to its top edge at higher frequencies demonstrates strong performance, maintaining over 80%
absorptivity (i.e., RL < −7 dB) in the 3.16 – 5.87 GHz band.
3.4. Experimental verification In summary, the experimental findings validated the

To validate the accuracy and reliability of the simulation sunflower-inspired metastructure’s excellent broadband
results, the sunflower-inspired metastructure was microwave absorption performance. In addition, Table 2
fabricated using FDM 3D printing, as shown in Figure 3. compares the performance of this metastructure with

Volume 4 Issue 3 (2025) 10 doi: 10.36922/MSAM025220048