Electromagnetic Scattering from Individual Crumpled Graphene Flakes: A Characteristic Modes Approach
Edward J. Garboczi, Jack F. Douglas, Luis Fernando Vargas Lara, Ahmed M. Hassan, Deb Chatterjee, Kalyan Durbhakula, Md Gaffar
Graphene flakes in real composites are rarely perfectly flat, and often exhibit complicated crumpled shapes. Therefore, the goal of this work was to quantify the electromagnetic scattering characteristics of individual crumpled graphene flakes with shapes resembling those found in real composites. The extinction cross sections of tens of graphene flakes, with different sizes and various levels of crumpleness, were calculated using multiple independent solvers. The results show that resonances in the extinction cross section spectrum decrease in amplitude as the graphene flakes become more crumpled. Moreover, some crumpled graphene flakes exhibited a broader resonance than that of perfectly flat graphene flakes. To explain these results, we used characteristic mode analysis to decompose the graphene surface currents into a set of fundamental currents or modes. For perfectly flat square graphene flakes, the vertical and horizontal modes were found to overlap and resonate at the same frequencies. However, as the graphene flakes became more crumpled, the horizontal/vertical symmetry broke down causing the corresponding modes to separate and resonate at different frequencies leading to an overall broader bandwidth. These results attest to the importance of modeling the exact shape of graphene flakes to accurately characterize their electromagnetic response.
, Douglas, J.
, , L.
, Hassan, A.
, Chatterjee, D.
, Durbhakula, K.
and Gaffar, M.
Electromagnetic Scattering from Individual Crumpled Graphene Flakes: A Characteristic Modes Approach, IEEE Antennas and Propagation Magazine
(Accessed February 28, 2024)