Terahertz Sensing Application by Using Fractal Geometries of Split-Ring Resonators

Abstract

Abstract-In this study, we report the simulation, fabrication and characterization of a dual-band fractal metamaterial used for terahertz sensing application. By applying the fractal structures of square Sierpinski (SS) curve to the split-ring resonators (SRRs), more compact size and higher sensitivity can be achieved as privileges over conventional SRRs. The influence of different geometrical parameters and the order of the fractal curve on the performances are investigated. Then overlayers are added to the fractal SRRs in order to explore the performance of the entire system in terms of sensing phenomenon. The changes in the transmission resonances are monitored upon variation of the overlayer thickness and permittivity. Measured results show good agreement with simulated data. At the second resonance of the second-order SS-SRRs, maximum frequency shifts of 19.8 GHz, 26.3 GHz and 37.8 GHz were observed for a 2 µm, 4 µm and 10 µm thickness of photoresist. The results show good sensitivity of the sensors suggesting they can be used for a myriad of terahertz sensing applications in biology and chemistry.

A review: metamaterial sensors for material characterization

“…Both these structures offered high field concentration than normal SRR at their confined region. Further, Nested SRR (He et al , 2011) and Square Sierpinski-SRR (Ma et al , 2013) were studied to attain miniaturization with high field confinement. Since these structures had more capacitive gaps compared to above discussed structures, miniaturization with high field confinement was attained.…”

Investigation on Metamaterial Antenna for Terahertz Applications

“…Yanbing Ma et al designed Square Sierpinski SRR (SS-SRR) for terahertz sensing application. They investigated the frequency response when the SS-SRR is implemented over the quartz substrate with the thickness as 130 µm [22]. Pozar et al designed and analyzed two types of printed antennas for millimeter wave communication such as patch and dipole.…”

Metamaterial-enhanced vibrational absorption spectroscopy for the detection of protein molecules

“…For example, molecular sensing in the THz region has become a key approach and has been widely studied 10 11 12 13 14 . A common method using a metamaterial (MM) is dielectric surface plasmon resonance sensing in the THz region, where the presence of molecules can be detected by the spectral shift caused by absorption of the molecules on the device 15 16 17 18 19 20 . Sensing with a split-ring resonator (SRR) is a typical example 9 10 13 15 16 17 21 22 .…”

“…A common method using a metamaterial (MM) is dielectric surface plasmon resonance sensing in the THz region, where the presence of molecules can be detected by the spectral shift caused by absorption of the molecules on the device 15 16 17 18 19 20 . Sensing with a split-ring resonator (SRR) is a typical example 9 10 13 15 16 17 21 22 . This structure is composed of a tiny gap area, whose resonant frequency can be well described by an equivalent LC circuit.…”