Highly Sensitive THz Refractive Index Sensor Based on Folded Split-Ring Metamaterial Graphene Resonators

Mohammad-Reza Nickpay,Ali Shahzadi,Mohammad Danaie

doi:10.1007/s11468-021-01512-8

Abstract

A highly sensitive absorption-based sensor based on folded split-ring metamaterial graphene resonators (FSRMGRs) is designed, and its biomedical application in terahertz (THz) spectrum is investigated. The sensor has a nearly perfect absorption, with a spectral absorption coefficient of 99.75% at 4 THz and an average Q-factor of 13.76. The resonance peak frequency is sensitive to the refractive index (RI) of the test medium (analyte), and a fairly high sensitivity of 851 GHz/RIU has been obtained. The specifications of the sensor can be tuned by an external DC-bias voltage applied to the graphene layer. According to the obtained results, the developed absorber appears to be a good candidate bio-sensing applications.

Highlights

The terahertz (THz) electromagnetic spectrum (0.3–10 THz) has attracted significant interest due to the unique features of its frequency band
We have proposed a high sensitivity refractive index (RI) sensor composed of an array of folded split ring MTMs graphene-based resonators (FSRMGRs)
Based on the results provided in Table. 1, the maximum sensitivity is 860 GHz/RIU which is a significant result compared to current research [57,58,59,60,61,62,63,64,65,66,67]

Summary

Introduction

The terahertz (THz) electromagnetic spectrum (0.3–10 THz) has attracted significant interest due to the unique features of its frequency band. MPA can be used as a RI sensor with a high sensitivity to changes in the characteristics of its environment [23,24,25,26,27]. The RI sensors based on the structure of the MTMs can have a high detection speed and low environmental damages, and they are excellent options for biomedical sensing [28,29,30,31,32]. A refractive index MTMs biosensor based on split-ring resonator (SRR) on a Teflon substrate with a sensitivity of 300 GHz/RIU is represented in [34]. We have proposed a high sensitivity RI sensor composed of an array of folded split ring MTMs graphene-based resonators (FSRMGRs). The outcome of the work indicates that the designed structure can be used for THz biomedical sensors applications

Graphene Conductivity

Structure design and numerical model

Results and discussion

Conclusion