Bistate Frequency Selective Surface based on Microfluidic Technology

In this paper, a reconfigurable frequency selective surface has been presented for bistate (transmittance/reflectance) operations. The proposed structure is designed based on microfluidic technology, where liquid metal alloy (eutectic gallium indium, EGaIn) is encased within a flexible dielectric substrate. The novelty of the design lies in its switching characteristic from dual-polarized allpass to polarization-selective bandpass/bandstop behavior, based on whether EGaIn is injected in the microchannels. The structure, being asymmetric in nature, exhibits bandpass behavior under vertical polarization, whereas it gives rise to bandstop response during orthogonal polarization. In addition, the design performs well under various angles of incidence for both the polarizations. The performances of the proposed structure is also validated by the measured responses of the fabricated prototype.