Design Of Gas Sensor With Left-Handed Materials

Left-handed material?LHM?is an artificial periodic structure with both permittivity and permeability being less than zero during the same frequency..Compared with ordinary materials,left-handed material is applied to sensors,stealth technology,filters and other microwave elements because of its electromagnetic properties.Left-handed material can be applied to sensors because left-handed material can enhance the localization of electromagnetic field and target,and magnify evanescent wave.This kind of sensors can break through the sensitivity and resolution of traditional sensors,and have the advantages of small volume,convenient adjustment of resonance characteristics and low loss.In recent years,with the rapid development of left-handed materials,more and more left-handed material sensors have been developed,such as displacement sensors,thin-film sensors,slot detective sensors,temperature and humidity sensors,etc.The real-time monitoring of gas in the current social environment is becoming more and more important.The miniaturized and intelligent gas sensors will be more consistent with the requirements of the times.In many environments,sensors are not suitable to replace batteries or wires.Therefore,passive wireless gas sensors are more suitable to market demand and can be used in inflammable and explosive environments.In this paper,a new type of gas sensor composed of CSRR micro-strip line left-hand structure and MoS₂ is proposed.According to the theoretical analysis of left-handed material,we can know that the SRR structure can produce steep and strong resonant signal,the gap between rings can also generate strong electric field.Those characters can improve the sensitivity and quality factors in sensing applications.The novel passive wireless gas sensor based on left-hand material is investigated by combining the structure of complementary split ring resonator?CSRR?with molybdenum disulfide?MoS₂?in this paper.A CSRR is etched in the ground plane of a integrated circuit board with grapheme-like molybdenum disulfide?MoS₂?between the gap on the top layer.Utilizing the gas adsorption of molybdenum disulfide to change the dielectric constant of the sensor,the sensor realizes passive wireless sensing with advantages of small volume,low cost,low power consumption,et al.The feasibility of the proposed gas sensor is simulated by the HFSS simulation software.The sensor structure is produced and measured and with 90MHz frequency shift.The parameters of the gas sensor such as resonance frequency shift and recovery time are demonstrated and analyzed.