A THz-TDS based metamaterial sensor for the sensitive distinguishment of food additives

A sensitive terahertz(THz)metamaterial sensor for the distinguishment of common additives in the food industry is proposed. The metamaterial sensor consists of an array of split ring resonator(SRR)with double tip ends. By checking resonate frequency shift of the sensor,the concentration and the type of the solution sample can be distinguished. The metamaterial sensor is fabricated on a quartz substrate,which is transparent for THz wave. The solutions with the concentration of 0. 2,0. 4,1. 5,2,3 and 4 mg/ml have been measured by using a terahertz time domain spectroscopy(THz-TDS). The results illustrate that the proposed metamaterial sensor can detect the concentration of the solution sample,as low as 0. 2 mg/ml. Meanwhile,different solutions with same concentration can also be clearly distinguished. Our study provides new insights for the application of terahertz metamaterial sensor based on SRR structure in the field of food safety.