Experimental reflectance spectra of MIM samples with increasing nanodisk diameters, starting from D ≥ 900 nm, are given in Fig. , and reveal the absorbance of said structures. Here all the probed metamaterial patterns were fabricated on the same Au coated Si substrate, which allowed to ensure polyimide layer thickness and composition consistency. For D = 900 nm nanodisks, when the metamaterial resonance is mostly decoupled from polyimide vibrational modes, the absorption peak is situated in the λ = 5 µm wavelength region and possesses a relatively narrow 600 nm FWHM width. Likely the main factor limiting the metasurface quality factor is the scattering due to nanoscale surface roughness, derived from a conformal transfer of the the polyimide layer roughness to the overlaying gold disks during their subsequent deposition. On the other hand, the PMDA-ODA polyimide insulator molecular vibration spectrum is dominated by four sharp and strong absorption peaks at 1736, 1509, 1388, 1253 cm -1 -respectively attributable to carbonyl stretching, aromatic amine ring-breathing, C-N stretch, and imide deformation modes -highlighted in Fig. ). Polyimide has several bands whose orientation can be used for determining molecular alignment: 1780, 1745, 1520 and 1400 cm -1 , which are respectively associated with C=O symmetric (chain axis), C=O asymmetric (ring tilt), C 6 H 5 aromatic rings (phenyl) tangential vibrations, and C-N-C axial stretch . The parallel (to film surface) bands are situated at 1491 cm -1 (ν C-C; skeletal vibration of 1,2,4-trisubstituted benzene ring in diamine moieties) and 1501 cm -1 (ν C-C; skeletal vibration of 1,4-disubstituted benzene in diamine moieties), while the perpendicular band is at 1724 cm -1 (ν C=O out of phase asymmetric stretching of carbonyl bonds in imide rings) .