A High Sensitivity Microfluidic Channel Enabled Terahertz Metamaterial Absorber For Sensing And Detectio

Metamaterials and metamaterial absorbers have been widely reported to be used in sensing and detection applications. Among them, metamaterial absorber is superior by its high-quality factor, and its high sensitivity to the change of the surrounding environment. However, the conventional metamaterials and metamaterial absorbers are configured with relatively thick substrates as their supporting structures with high permittivity, which compromises the sensitivity. Herein we utilize thin silicon nitride membrane as the supporting structure for the metamaterial layer to eliminate the high permittivity effect of the bulk substrate to achieve a much higher sensitivity. Moreover, we find the sensitivity can be further increased with thicker spacer thickness. The fabricated devices demonstrate a more than 3 times improvement in sensitivity compared with the state of art.