Flexible Sub-THz Metal Wire Grid Polarizer Based on an EGaIn $_{24.5}$ Alloy

A flexible sub-THz polarizer based on an eutectic Gallium-Indium alloy (EGaIn
_24.5
) on a vinyl acetate substrate is fabricated and tested. The EGaIn
_24.5
alloy shows low melting point, good wettability, and high conductivity, resulting in a low-cost alternative to conductive inks based on metal nanoparticles. These properties are exploited to draw metal wire grid polarizers by using a technical pen on a bendable sheet of vinyl acetate monomer. Measurements are carried out with a transmission THzTDS setup in the frequency range from 0.1 to 0.6 THz, showing an extinction ratio up to 20 dB. This approach allows a quick low-tech and cost effective implementation of flexible polarizers in the sub-THz band.