Research Of Terahertz Metamaterial Based On MEMS Technology

Metamaterials is an artificial composite electromagnetic material whichincorporating periodic subwavelength metal resonators unit. Metamaterials canachieve a special electromagnetic properties through designing the unit structurerationally, including cloaking, perfect absorber and the negative refractive index.In recent years, with the rapid development of terahertz (THz) technology, theTHz metamaterial devices have also become a research hotspot. The THzmetamaterials also has a broad promising application in THz imaging,spectroscopy, and biosensors field. This paper demonstrates the research of THzmetamaerials based on MEMS technology, including symmetrical double splitring (DS-SRR) filters which can achieve bandpass and lowpass filtering effect,biosensor, and switching electromagnetically induced transparency (EIT) inreconfigurable THz metamaterials. The main research work are as follows:(1) Designed and fabricated the periodic array DS-SRR THz metamaterialfilters. We analyzed the filter structure by CST Microwave Studio. In order toimprove the transmittance of the metamaterial device, we manufactured thefilters on high-resistivity silicon and flexible PET films substrates by MEMSprocess, and tested the THz transmission spectrum of the metamaterial filters.The results demonstrated experiment and simulation are almost identical.(2) Fabricated three kinds of metamaterials biosensor microfluidic chips,including a single split ring structure, asymmetric dual splits ring structure andcounterchange structure. The experimental procedure comprised CST simulationanalysis, MEMS sensor device preparing process, the preparation of PDMSpackaging mold, chip bonding and biological modification, etc. The chip weremodified by GGT-2antibody (100μg/ml) samples, and the THz-TDStransmittance test results showed that the maximum frequency shift ofasymmetric spilt ring structure is19GHz from0.4to1.2THz before and after modification, and the sensitivity of this structure is excellent.(3) Analyzed the EIT effect of the metamaterial structure by CST software.When Δx is17μm, the EIT effect is strongest, and the transparent windowformant appears1.449THz, the amplitude is75.7%. By analyzing the generationmechanism of the formant, terahertz transmission spectrum, surface currentdistribution and phase delay characteristics, the dynamic tuning characteristics ofthe EIT effect is verified by the theoretical data.